Mon May 31 2021 12:19:12 PDT
  • Whiteboard: [qf:
1776 bugs found.
ID Type Summary Product Comp Assignee Status Resolution Updated
219276 Cache parsed stylesheets Core CSS Parsing and Comp nobody RESO DUPL 2020-07-12
519514 [meta] Add an asynchronous bookmarking API Toolkit Places nobody NEW --- 2020-11-09
575614 {inc} Resizing window is slow for long list with multicol (from "-moz-column-count: 3" or "column-width: 20em;") Core Layout: Columns nobody NEW --- 2020-08-17
613498 Very slow chrome to content DOM access Core XPConnect nobody NEW --- 2021-04-21
614163 Slow property access on dromaeo's "jQuery -attr(class) x 100" benchmark Core JavaScript Engine nobody NEW --- 2018-04-08
627220 Finalize external strings in the background Core JavaScript: GC jdemooij RESO FIXE 2017-08-10
646937 throttle animation in completely obscured windows (virtual desktop, minimised, hidden behind other fullscreened windows) Core Widget nobody NEW --- 2021-02-18
651049 Write a new off-the-main-thread IO driver for expat Core XML nobody NEW --- 2020-03-05
651120 [Meta] Remove DOM node child array storage Core DOM: Core & HTML bugs RESO FIXE 2018-11-08
661590 Repeated calls to location.hash = "#foo" cause large amounts of disk activity Toolkit Places mak ASSI --- 2021-05-23
661768 Defer history lookup on anchor creation Core DOM: Core & HTML nobody NEW --- 2020-03-13
691507 [meta] Periodic hangs in the UI due to Places Toolkit Places nobody NEW --- 2019-04-22
699850 [meta] Refactor all synchronous history APIs to use async Storage APIs Toolkit Places nobody RESO FIXE 2018-07-05
734643 Extremely slow deleting from history (seems some O(n^2) algorithm is there) Firefox Bookmarks & History nobody NEW --- 02:29:57
760888 IE10 Test Drive: ParticleAcceleration Canvas 2D demo is slow Core Canvas: 2D nobody NEW --- 2018-10-29
789945 Save preferences asynchronously Core Preferences: Backend milaninbugzilla RESO FIXE 2017-08-10
803709 We appear to be copying large data URIs over and over in nsSimpleURI. Core Networking nobody NEW --- 2020-08-10
816784 Lots of time spent in WindowDestroyedEvent::Run/js::NukeCrossCompartmentWrappers when closing tabs/windows Core DOM: Core & HTML janus926 RESO FIXE 2019-03-13
827440 nsIconChannel::AsyncOpen can block Core ImageLib nobody NEW --- 2018-01-16
827937 Opening huge mercurial long commit page freezing Firefox Core Layout nobody NEW --- 2021-04-17
827976 Creating the hidden window lazily on non-Mac platforms Core General felipc RESO FIXE 2019-04-10
828240 Create a single nsDisplayTransform for children-only transforms Core SVG jwatt RESO FIXE 2019-04-09
862178 CrashSubmit.jsm / KeyValueParser.jsm do a lot of main thread file I/O Toolkit Crash Reporting me RESO FIXE 2018-02-06
866102 ellipsis multiple lines text doesn't work (i.e. add support for -webkit-line-clamp) Core CSS Parsing and Comp cam RESO FIXE 2021-01-18
867798 Cookie Service closes DB on main thread Core Networking: Cookies CuveeHsu RESO FIXE 2017-08-09
870460 Lazy load of cookie service blocks main thread while cookie database loads Core Networking: Cookies CuveeHsu RESO FIXE 2019-03-12
886907 Remove old synchronous contentPrefService from the tree Toolkit General VYV03354 RESO FIXE 2017-08-16
887887 Use Sqlite.jsm in Form History Toolkit Form Manager nobody NEW --- 2018-03-07
888784 FormHistory.jsm migration and DB creation should be off the main thread Toolkit Form Manager mconley RESO FIXE 2018-01-23
900784 [meta] Add start-up cache for any JavaScript code. Core JavaScript Engine nicolas.b.pierron RESO FIXE 2021-05-05
903519 GC: allocate JSStrings and string data in the Nursery Core JavaScript: GC sphink RESO FIXE 2018-08-31
906076 [meta] Virtual tabs - lazily create linkedBrowser and other dependent elements for tabbrowser tabs to improve startup performance Firefox Tabbed Browser u462496 RESO FIXE 2020-07-07
912717 [Session Restore] SessionCookies blocks while recursively extracting host data information from history entries Firefox Session Restore ttaubert RESO FIXE 2021-02-24
917090 Visibility state is not updated when the browser window is obscured or on another workspace Firefox General esmyth NEW --- 2019-09-05
920187 Deprecate and get rid of FileUtils.getFile() Toolkit General nobody NEW --- 2020-07-13
922272 Handle jQuery polymorphic selector argument better Core JavaScript Engine: J nobody RESO FIXE 2018-01-05
934607 nsHtml5TreeBuilder::startTokenization takes significant amount time when parsing small innerHTML strings Core DOM: HTML Parser nobody RESO FIXE 2017-05-31
936338 Chrome is more responsive on the D3.js based MIT Media Lab's Immersion application Core Graphics: Layers nobody NEW --- 2018-12-18
944127 [Meta] jQuery $("<div>") DOM element append test is 1.3x slower than Chrome Core DOM: Core & HTML bugs RESO INCO 2019-03-13
979280 [meta]Replace the synchronous transaction manager in places with an asynchronous one Toolkit Places nobody RESO FIXE 2018-03-02
984690 Optimize GetRootPresContext() to avoid going through the viewmanager / view tree Core Layout nobody NEW --- 2020-10-30
1022988 [e10s] Speedometer benchmark regresses significantly in e10s mode Core General mrbkap RESO WORK 2017-08-11
1034599 Convert remaining Promise.defer() uses to PromiseUtils.defer() or to an inline helper Toolkit Async Tooling florian RESO FIXE 2017-06-26
1038099 Consider creating Latin1 inline strings in JS_NewExternalString if the string is short Core JavaScript Engine jwalden RESO FIXE 2018-02-28
1058899 Unnecessary XPIProviderUtils.js / extensions.json load at startup for profiles with only bootstrap add-ons Toolkit Add-ons Manager nobody RESO DUPL 2017-06-23
1061886 incremental asynchronous parsing Core JavaScript Engine nobody RESO INAC 2019-05-27
1071513 Enable async PlacesTransactions in Nightly Firefox Bookmarks & History standard8 RESO FIXE 2018-03-06
1094812 Use Bookmarks.jsm in browser-places.js Firefox Bookmarks & History standard8 RESO FIXE 2017-08-02
1094818 Use Bookmarks.jsm in controller.js Firefox Bookmarks & History mak RESO FIXE 2017-08-02
1095425 Convert PlacesTransactions to the new Bookmarks.jsm API Toolkit Places mak RESO FIXE 2017-07-09
1095426 Convert JSON backups code to the new Bookmarks.jsm API Toolkit Places standard8 VERI FIXE 2017-11-09
1095427 Convert BookmarkHTMLUtils code to the new Bookmarks.jsm API Toolkit Places standard8 RESO FIXE 2018-06-29
1097376 Poor performance in Ember app Discourse Core JavaScript Engine nobody NEW --- 2018-08-10
1100357 Async transform animations are disabled for large layers Core Layout nobody RESO FIXE 2020-08-02
1107364 move findNodeByDetails to treeView.js and make it use an hash Firefox Bookmarks & History i.milind.luthra RESO FIXE 2017-06-26
1107626 Evaluate aggregating timers to reduce the number of times we wake up the CPU for serving them Core DOM: Core & HTML nobody NEW --- 2021-02-05
1118086 [e10s] There is a delay for about 1 seconds to display <select> drop-down list with 1600+ items Core Layout: Form Control dothayer ASSI --- 2020-05-27
1131937 Dramatically high CPU usage on facebook group page Core Layout bugs RESO WORK 2017-11-28
1133423 setting an already-existing expando property on document is very slow Core JavaScript Engine: J jdemooij RESO FIXE 2017-03-22
1134611 Optimize Object.defineProperty Core JavaScript Engine nobody VERI DUPL 2017-07-31
1138151 Scrolling on some specific pages causes Firefox to use HDD constantly and loudly Toolkit Places nobody NEW --- 2019-11-29
1141547 [meta] Deprecate synchronous Bookmarks API (Milestone 1) Toolkit Places nobody RESO FIXE 2017-11-03
1149732 GMPInstallManager does a main thread IO in nsZipArchive::ExtractFile Toolkit General spohl.mozilla.bugs RESO FIXE 2017-06-14
1152625 Support AES HW acceleration on ARMv8 NSS Libraries m_kato RESO FIXE 2020-08-28
1154987 [Meta] Move JS parsing off of main thread and enable incremental parsing Core JavaScript Engine kvijayan ASSI --- 2018-11-24
1156934 Be more efficient with how we update the LookAndFeel int cache in the content process Core Widget emilio RESO FIXE 2020-06-01
1162665 ES6 Map performance for large numbers of elements is deficient Core JavaScript: GC nobody NEW --- 2019-07-03
1162698 Thumbnail generation should have a time limit Firefox New Tab Page nobody NEW --- 2019-06-28
1166166 Shrink Sqlite memory on the async thread when possible. Toolkit Storage dothayer RESO FIXE 2017-06-20
1167452 Incrementalize weak marking phase Core JavaScript: GC sphink RESO FIXE 2020-06-18
1167472 Make classes work in the JITs. Core JavaScript Engine: J nobody NEW --- 2020-02-19
1168606 Implement preloading cursors for IndexedDB Core Storage: IndexedDB simon.giesecke RESO FIXE 2019-12-12
1176050 Firefox liveload with lots of connections slow when netmonitor is open DevTools Netmonitor nobody RESO FIXE 2020-02-05
1184569 Firefox janks hard when loading a Google Docs presentation Core JavaScript Engine nobody NEW --- 2018-11-24
1186409 Use a single global for all JSMs Core XPConnect continuation RESO FIXE 2017-09-19
1189632 Decode Blob off the main thread in createImageBitmap() Core Canvas: 2D nobody RESO DUPL 2017-11-24
1190679 [meta] Run WebExtensions out of process WebExtensions General nobody NEW --- 2020-04-06
1194751 PScreenManager should not use sync messages Core DOM: Content Process kanru RESO FIXE 2018-07-16
1196094 Use e10s when creating the PGO profile Firefox Build System General gijskruitbosch+bugs RESO FIXE 2019-07-12
1213513 2D canvas+HTML/CSS animation demo site broken on Firefox, works great on Chrome Core DOM: Animation nobody NEW --- 2019-04-16
1217748 On/Off opacity changes shouldn't create active layers Core Layout nobody NEW --- 2018-10-29
1222086 Block JavaScript parser thread when source code characters are not available Core JavaScript Engine ydelendik NEW --- 2017-10-06
1222633 Add support for <link rel=preload> Core DOM: Core & HTML dd.mozilla RESO FIXE 2020-05-17
1223270 Add support for texture recycling to ffmpeg backend on Windows Core Audio/Video: Playbac jya-moz RESO FIXE 2018-07-28
1231711 [meta] Port OS.File to C++ Toolkit OS.File brennie NEW --- 2021-03-05
1232023 cloneNode slower than in Chrome Core DOM: Core & HTML ksteuber RESO FIXE 2019-03-13
1236016 Sync transaction during scrolling on soundcloud Core Graphics: Layers nobody RESO FIXE 2017-03-27
1236104 Allow scripts from pre-load cache to be off-thread compiled. Core JavaScript Engine nobody REOP --- 2021-03-29
1236512 document.hidden is not set to true when window is completely covered by another non-translucent application Core DOM: Core & HTML echen RESO FIXE 2021-02-23
1237454 [Power] Optimize animations in visibility:hidden elements Core Layout hikezoe.birchill RESO FIXE 2021-04-26
1241091 Poor performance on JS frameworks benchmark Core JavaScript Engine nobody NEW --- 2020-04-12
1242861 Google Inbox slow and cpu intensive Core JavaScript Engine nobody NEW --- 2020-04-17
1245279 Various tests in Speedometer seem to spend quite a bit time in jS Core JavaScript Engine nobody NEW --- 2020-04-12
1246410 Low performance of texImage2D with canvas2d and WebGL Core Canvas: WebGL nobody NEW --- 2019-06-04
1250473 [e10s] convert formSubmitListener.js to a process script instead of a frame script Toolkit Form Manager ehsan.akhgari RESO FIXE 2017-04-15
1250823 Firefox hangs when setting innerHtml in rich text editor Core DOM: HTML Parser masayuki RESO FIXE 2020-05-06
1253394 jquery performance increases if the page is displayed in a iframe Core Layout nobody UNCO --- 2021-03-15
1257565 Allow switching blocklist from XML to Remote Settings diff-based sync Toolkit Blocklist Implementa gijskruitbosch+bugs RESO FIXE 2019-12-09
1259927 [meta] CacheIR tracking bug Core JavaScript Engine: J nobody NEW --- 2021-04-07
1260981 [Meta] Identify the cause of performance problems in using google docs Firefox General nobody NEW --- 2018-11-26
1261484 Optimize position:static <--> position:relative changes to avoid jank from massive frame reconstruction Core Layout nobody NEW --- 2019-12-27
1264535 [perf][google suite][google docs] 61.03%(7867ms) slower than Chrome when scrolling a file with 3 pages by page down key Core General nobody RESO INCO 2018-11-29
1265824 Add a ClientStorageTextureSource Core Graphics: Layers dothayer RESO FIXE 2019-07-11
1265980 Running jasmine is slower than Safari and Chrome Core JavaScript Engine nobody NEW --- 2020-10-18
1266140 Object.keys 50% slower than for...in Core JavaScript Engine nobody UNCO --- 2018-08-23
1267075 Convert dom/base/nsImageLoadingContent.cpp to use AsyncOpen2 Core DOM: Security allstars.chh RESO FIXE 2018-04-06
1267971 "nsInputStreamPump::OnStateStop" spent more time between navigationStart and loadEventEnd Core General nobody RESO INCO 2017-09-18
1268140 Momentum scrolling interrupted on YouTube user pages Core Panning and Zooming nobody RESO DUPL 2021-01-15
1269666 [perf][google suite][google docs] 284.06%(146478ms) slower than Chrome when creating 3 page content and replace the keyword 15 times Core General nobody RESO WORK 2017-05-16
1269684 [perf][google suite][google docs] 260.31%(718472 ms) slower than Chrome when creating 10 page mix content(txt/img/table) and change txt formating Core General nobody RESO INCO 2018-11-29
1269690 [perf][google suite][google docs] 45.25%(4528ms) slower than Chrome when opening 1 page table content Core JavaScript Engine kvijayan ASSI --- 2020-04-16
1269698 [perf][google suite][google docs] 88.01%(7750 ms) slower than Chrome when opening 1 page UTF8 content Core JavaScript Engine nobody NEW --- 2018-07-24
1270056 [Perf][google suite][google docs] Try to prevent the GC before first paint event Core JavaScript: GC nobody RESO FIXE 2017-03-07
1270059 make setTimeout() low priority during page load Core Performance rjesup RESO FIXE 2020-09-05
1270351 "nsJSUtils::EvaluateString" spent more time between navigationStart and loadEventEnd Core General nobody RESO INCO 2017-09-18
1270427 "nsRefreshDriver::Tick" spent more time between "domLoading" to "loadEventEnd" Core General nobody RESO INCO 2017-09-18
1270737 "nsRefreshDriver::Tick" spent more time when clicking Page Down Core General nobody RESO INCO 2017-09-18
1270739 "EventDispatcher::Dispatch" spent more time when clicking Page Down Core General nobody RESO INCO 2017-09-18
1271512 "nsRefreshDriver::Tick" spent more time between "navigationStart" to "domLoading" Core General nobody RESO INCO 2017-09-18
1271543 "EventDispatcher::Dispatch" spent more time when typing Core General nobody RESO INCO 2017-09-18
1271914 "js::RunScript" spent more time between "domLoading" to "loadEventEnd" Core General nobody RESO INCO 2017-09-18
1271936 "nsViewManager:DispatchEvent" spent more time when change the font to bold Core General nobody RESO INCO 2017-09-18
1271943 "nsRefreshDriver::Tick" spent more time when inserting image Core General nobody RESO INCO 2017-09-18
1272147 Long GC times while loading Facebook newsfeed Core JavaScript: GC nobody RESO WORK 2017-10-16
1272196 "nsViewManager:DispatchEvent" spent more time when inserting table Core General nobody RESO INCO 2017-09-18
1272567 "nsInputStreamPump::OnStateStop" spent more time between "domLoading" and "loadEventEnd" Core General nobody RESO INCO 2017-09-18
1273303 style sheet additions (etc.) should check that rules might apply to the current document Core CSS Parsing and Comp bugs RESO WONT 2017-11-21
1277206 Performance degradation in heavy CSS / Javascript interactive text. Core Graphics bas ASSI --- 2019-09-03
1278554 CanvasRenderingContext2D::DrawImage takes lots of time when scrolling Google Spreadsheet Core Canvas: 2D bignose1007+bugzilla ASSI --- 2020-10-11
1280802 Angular framework performance test spends 10% in nursery GC Core JavaScript: GC nobody NEW --- 2018-11-15
1285182 [perf][google suite][google docs] 25.64%(2100 ms) slower than Chrome when opening 1 page UTF8 content Core JavaScript Engine nobody RESO WORK 2018-10-09
1285355 [meta] Make it possible to do only zone GCs Core JavaScript: GC nobody RESO FIXE 2018-12-06
1287027 [google suite][google docs] FirstPaint/FirstVisualChange much slower loading a 1 page (UTF-8) google doc Core Performance nobody NEW --- 2020-04-15
1287041 [perf][google suite][google docs] 53.14%(4800ms) slower than Chrome when opening 1 page text content Core General nobody RESO INCO 2017-06-02
1287055 [perf][google suite][google docs] 31.65%(12283ms) slower than Chrome when creating 10 tables (edit) Core General nobody RESO INCO 2018-12-13
1287418 Noticeable delay in autocomplete popup display Firefox Address Bar nobody NEW --- 2019-12-18
1288602 [Meta] Identify the cause of performance problems in using Facebook Core General nobody RESO INAC 2018-12-12
1290776 Long list of nodes with mousedown event poor performance Core Layout nobody NEW --- 2018-05-07
1294625 Try to tick refresh driver during html parsing Core Layout bignose1007+bugzilla NEW --- 2017-10-06
1296161 Measure and solve sync reflow for studying gdoc performance. Core Layout nobody NEW --- 2017-10-06
1298380 [Meta] Enable Progressive Web Metrics for Telemetry & Profiling Core General nobody NEW --- 2020-02-20
1298381 Implement Time to First Contentful Paint (TTFCP) for Telemetry/Profiler Core Layout rjesup RESO FIXE 2019-12-16
1298816 JitcodeGlobalTable::markUnconditionally is taking a lot of time when the profiler is running Core JavaScript: GC sphink RESO FIXE 2017-04-26
1299118 Implement Time to Interactive (TTI) for Telemetry/Profiler Core Layout rjesup RESO FIXE 2018-10-23
1299643 [meta] Google Docs performance issues due to javascript execution Core JavaScript Engine nobody NEW --- 2020-05-20
1303296 Implement Expected Queueing Time (EQT) for Telemetry/Profiler Core DOM: Events nobody NEW --- 2018-11-25
1303313 Implement Frame Throughput (FT) for Telemetry/Profiler Core Graphics nobody RESO INCO 2018-11-16
1303335 Creating the result object for Object.getOwnPropertyDescriptor is slow Core JavaScript: Standard till RESO FIXE 2017-12-05
1303749 Spell checker might be using sync IPC messages for every word. Core Spelling checker nobody RESO DUPL 2019-01-22
1307024 [Perf] [google docs] Firefox will get 3~9% faster when running gdoc test cases with chrome user agent Core General nobody NEW --- 2020-02-07
1307134 MousePosTracker flushes layout on mouse move (via mozInnerScreenX/Y) Core DOM: Core & HTML dbaron VERI FIXE 2017-08-10
1307244 [Meta] Perceived Performance Measures Core General nobody NEW --- 2019-07-29
1307262 slow animations at https://coolstar.org/misc/mikurain/ Core Web Painting nobody NEW --- 2017-10-06
1308111 [Meta] Identify the cause of performance problems in using google slides Firefox General nobody RESO INAC 2018-12-12
1308112 [Meta] Identify the cause of performance problems in using google sheets Firefox General nobody RESO WONT 2018-11-27
1308660 for background tabs, break refresh driver tick into multiple events off the main thread's event loop Core Layout bugs NEW --- 2019-11-06
1308876 Nested inline-blocks with matching width locks up browser due to O(2^depth) reflow performance Core Layout dbaron RESO FIXE 2021-04-13
1310295 Make left pane queries virtual Toolkit Places standard8 RESO FIXE 2018-07-02
1311425 Make requestIdleCallback aware of timeouts Core DOM: Core & HTML afarre RESO FIXE 2019-03-13
1313465 Measure event to display latency (INPUT_EVENT_RENDER_MS) Toolkit Performance Monitori legnaleurc RESO INAC 2019-07-23
1314861 Lazily load built-in SDK modules Add-on SDK Graveyard General kmaglione+bmo RESO FIXE 2017-07-07
1315098 Firefox causing constant fan spin with big pauses, and high GC/CC Core XPCOM nobody RESO INCO 2018-01-09
1316864 Google Apps extremely slow -- scrolling, updating text, etc -- unusable Core JavaScript Engine nobody NEW --- 2018-03-05
1316901 Fatal performance in Facebook comments Core JavaScript Engine nobody RESO WORK 2017-03-29
1318095 Expose Navigation Timings as profiler markers for top level content Toolkit Performance Monitori mstange.moz RESO FIXE 2017-04-27
1318124 Move metadata for non-blank paint marker into data payload Core Gecko Profiler mstange.moz NEW --- 2018-07-11
1319087 CacheIR: optimize cross-compartment wrappers Core JavaScript Engine: J evilpies RESO FIXE 2018-02-28
1320534 [meta] Speed and performance of importing bookmarks from JSON or HTML files is awful Firefox Bookmarks & History nobody NEW --- 2019-07-01
1322235 The extension policy service is too slow and used on hot code paths WebExtensions Request Handling kmaglione+bmo RESO FIXE 2018-08-22
1323083 Change mark bit interpretation to allow incremental gray marking Core JavaScript: GC jcoppeard RESO FIXE 2018-05-22
1323521 Prevent Windows 10 touchscreens from launching a11y Core Widget: Win32 aklotz VERI FIXE 2017-03-29
1324649 Background color change does not follow the cursor quickly enough on GMail Core JavaScript Engine nobody RESO WORK 2017-06-12
1325054 Browsing Facebook causes hangs Core Networking: HTTP hchang.mozilla RESO FIXE 2017-05-04
1325254 optimize TimerThread data structures Core XPCOM bzbarsky RESO FIXE 2017-09-21
1326344 [Perf][Gslide] 48.37%(6683 ms) slower than Chrome when creating one slide for 5 pages slide on GSlide Firefox General nobody RESO INAC 2018-12-12
1329486 Poor HTTPs performance. Firefox 50.1.0 windows vs Chrome. Speedtest Core Networking nobody UNCO --- 2020-06-07
1329601 Investigate a slow reflow case for Google Docs Core Layout sean NEW --- 2021-04-17
1329888 Gecko profiler mistakenly shows _platform_bzero$VARIANT$Haswell being called from arena_dalloc (instead of arena_malloc) Core Gecko Profiler mstange.moz RESO WONT 2017-05-03
1329900 GC takes a long time on the test case in bug 1269695 Core JavaScript: GC nobody NEW --- 2018-04-19
1329923 Emit profiler markers for discarding Ion code Core JavaScript Engine: J nobody REOP --- 2017-10-06
1330249 IonBuilder::build() is too slow when loading GSlides Core JavaScript Engine: J nobody RESO DUPL 2017-04-10
1330375 interleaved innerText calls and display:none sets trigger significantly more reflow overhead than chrome Core Layout: Tables u480271 RESO FIXE 2020-05-09
1330460 Prevent touchscreens on Windows 8.x from instantiating accessibility (64-bit builds) Core Widget: Win32 davidp99 RESO FIXE 2017-03-29
1330475 Node.textContent is slow in some cases Core DOM: Core & HTML nobody RESO WORK 2020-01-26
1330547 Firefox is slower than Chrome to open a single empty slide presentation in Google Slides Core General nobody NEW --- 2017-10-06
1330912 Don't init spell checker for spellcheck=false contentEditable Core DOM: Editor m_kato RESO FIXE 2017-05-16
1331542 EndTransaction() takes 25% of time of PaintFrame() when scrolling a gdoc with 200+ pages. Core Web Painting howareyou322 RESO WORK 2017-03-20
1331674 [meta] Stop doing sync IPC from the content process or the UI thread Core DOM: Core & HTML nobody NEW --- 2020-02-04
1331680 Consider not doing sync IPC for document.cookie getter/setter Core Networking: Cookies amchung RESO FIXE 2018-08-16
1331684 RemoteAddonsChild.jsm shouldLoad sync IPC messages are too expensive Toolkit General kmaglione+bmo RESO WONT 2017-04-04
1331718 Make DisplayItemData more readily available Core Web Painting bas RESO FIXE 2018-11-13
1332578 Caching info. on items from frame tree or DOM-tree may improve performance of painting Core Web Painting thinker.li RESO WONT 2019-05-02
1334263 Expandos are really slow to access Core XPConnect nobody RESO DUPL 2017-04-12
1334524 [meta] QF - Google Docs Core General nobody RESO INCO 2017-09-18
1334605 01 - gdoc_create_copypaste_image_1 Core General nobody RESO INCO 2017-09-18
1334607 02 - gdoc_create_copypaste_txt_1 Core General nobody RESO INCO 2017-09-18
1334631 [meta] QF - Google Sheets Core General nobody RESO WONT 2018-12-11
1334632 [meta] QF - Google Slides Core General nobody RESO INAC 2018-12-12
1334635 Synchronous flush when closing a window Firefox Bookmarks & History enndeakin RESO FIXE 2017-05-09
1334642 Synchronous flush when activating/deactivating a window Firefox Theme sfoster VERI FIXE 2017-09-11
1334655 PCompositorBridge::Msg_WillClose can block the UI thread when closing a window Core Graphics: Layers nobody NEW --- 2020-10-30
1335105 [meta] 01-gsheet_1000r_number_chars Core General nobody RESO INCO 2018-11-27
1335137 [meta] 02-gsheet_1000r_number_chars_1000formula Core General nobody RESO INCO 2018-11-27
1335140 [meta] 03-gsheet_1000r_number_chars_1000formula_deletecell Core General nobody RESO INCO 2018-11-27
1335143 04-gsheet_1000r_number_chars_1000formula_modifycell Core General nobody RESO INCO 2018-11-26
1335144 05-gsheet_1000r_number_chars_deleteallcell Core General nobody RESO INCO 2018-11-27
1335361 06-gsheet_1000r_number_chars_scrolldown Core General nobody RESO INCO 2018-11-27
1335363 07-gsheet_100r_different_color Core General nobody RESO INCO 2018-11-27
1335364 08-gsheet_100r_different_color_switchtab Core General nobody RESO WONT 2018-11-27
1335366 09-gsheet_100r_number_chars Core General nobody RESO WONT 2018-11-27
1335367 10-gsheet_100r_number_chars_100formula_10tabs Core General nobody RESO WONT 2018-11-27
1335369 11-gsheet_100r_number_chars_100formula_switchtab Core General nobody RESO WONT 2018-11-27
1335375 12-gsheet_100r_number_chars_10tabs_scrolldown Core General nobody RESO WONT 2018-11-27
1335376 13-gsheet_100r_number_chars_chart Core General nobody RESO WONT 2018-11-27
1335377 14-gsheet_100r_number_chars_chart_100formula Core General nobody RESO WONT 2018-11-27
1335380 15-gsheet_100r_number_chars_chart_switchtab Core General nobody RESO WONT 2018-11-27
1335382 16-gsheet_100r_number_chars_image Core General nobody RESO WONT 2018-11-27
1335383 17-gsheet_100r_number_chars_image_switchtab Core General nobody RESO WONT 2018-11-27
1335384 18-gsheet_100r_number_utf8chars Core General nobody RESO WONT 2018-11-27
1335385 19-gsheet_100r_number_utf8chars_10tabs Core General nobody RESO WONT 2018-11-27
1335387 20-gsheet_100r_number_utf8chars_scrolldown Core General nobody RESO WONT 2018-11-27
1335756 01-gslide_create_slide_1 Core General nobody RESO WONT 2018-12-01
1335757 02-gslide_create_slide_30 Core General nobody RESO WONT 2018-12-01
1335758 03-gslide_create_slide_5 Core General nobody RESO WONT 2018-12-01
1335767 04-gslide_delete_slide_10 Core General nobody RESO WONT 2018-12-01
1335770 05-gslide_read_animation_2 Core General nobody RESO WONT 2018-12-01
1335775 06-gslide_read_blank_1 Core General nobody RESO WONT 2018-12-01
1335781 07-gslide_read_image_chart_1 Core General nobody RESO WONT 2018-12-01
1335782 08-gslide_read_image_chart_5 Core General nobody RESO WONT 2018-12-01
1335783 09-gslide_read_mix_content_50 Core General nobody RESO WONT 2018-12-01
1335786 10-gslide_read_mix_content_presentation_30 Core General nobody RESO WONT 2018-12-01
1335787 11-gslide_read_shape_1 Core General nobody RESO WONT 2018-12-01
1335791 12-gslide_read_table_1 Core General nobody RESO WONT 2018-12-01
1335793 13-gslide_read_txt_1 Core General nobody RESO WONT 2018-12-01
1335797 14-gslide_read_utf8_txt_1 Core General nobody RESO WONT 2018-12-01
1335798 15-gslide_read_utf8_txt_10 Core General nobody RESO WONT 2018-12-01
1335802 16-gslide_update_layout_5 Core General nobody RESO WONT 2018-12-01
1335803 17-gslide_update_text_10 Core General nobody RESO WONT 2018-12-01
1335804 18-gslide_update_text_5 Core General nobody RESO WONT 2018-12-01
1335805 19-gslide_update_theme_10 Core General nobody RESO WONT 2018-12-01
1335808 20-gslide_update_theme_30 Core General nobody RESO WONT 2018-12-01
1336100 03-gdoc_create_image_1 Core General nobody RESO INCO 2017-09-18
1336102 04-gdoc_create_txt_1 Core General nobody RESO INCO 2017-09-18
1336105 05-gdoc_create_typing_1 Core General nobody RESO INCO 2017-09-18
1336108 06-gdoc_create_typing_100 Core General nobody RESO INVA 2017-06-09
1336109 07-gdoc_delete_basic_image_1 Core General nobody RESO INCO 2017-09-18
1336110 08-gdoc_delete_basic_table_1 Core General nobody RESO INCO 2017-09-18
1336111 09-gdoc_delete_basic_txt_1 Core General nobody RESO INCO 2017-09-18
1336115 10-gdoc_load Core General nobody RESO INCO 2017-09-18
1336118 11-gdoc_load_file Core General nobody RESO INCO 2017-09-18
1336121 12-gdoc_pagedown Core General nobody RESO INCO 2017-09-18
1336160 13-gdoc_pageend Core General nobody RESO INCO 2017-09-18
1336161 14-gdoc_pd3 Core General nobody RESO INCO 2017-09-18
1336162 15-gdoc_read_basic_image_1 Core General nobody RESO INCO 2017-09-18
1336164 16-gdoc_read_basic_table_1 Core General nobody RESO INCO 2017-09-18
1336165 17-gdoc_read_basic_txt_1 Core General nobody RESO INCO 2017-09-18
1336167 18-gdoc_read_utf8_txt_1 Core JavaScript Engine nobody RESO INCO 2017-09-18
1336169 19-gdoc_update_replace_3 Core General nobody RESO INCO 2017-09-18
1336171 20-gdoc_update_undoredo_100 Core General nobody RESO INCO 2017-09-18
1336173 [meta] QF - Websites Core General nobody NEW --- 2018-09-05
1336579 Attach SetProp Function prototype Core JavaScript Engine: J jdemooij RESO FIXE 2017-04-10
1336763 Only message for permitUnload on tabs that have indicated that they contain a frame that has a beforeunload handler Core DOM: Content Process mconley RESO FIXE 2019-04-09
1337056 Switch permission manager initialization to be async Core Permission Manager nika RESO FIXE 2017-07-10
1337058 Switch the PContent FindPlugins message to happen asynchronously Core Plug-ins kyle RESO FIXE 2017-06-07
1337062 PContent::Msg_GetGfxVars can take a long time Core Graphics milaninbugzilla RESO FIXE 2017-06-29
1337063 PContent::Msg_GetGraphicsDeviceInitData can take a long time Core Graphics gsquelart RESO FIXE 2017-08-02
1337064 Make tab ID allocation asynchronous Core IPC freesamael RESO FIXE 2017-04-28
1337080 Switch GMP initialization to be asynchronous Core Audio/Video: GMP chris RESO WONT 2019-06-17
1337764 Attach In stub for proxies Core JavaScript Engine: J tcampbell RESO DUPL 2017-09-26
1337773 Add an Ion IC for JSOP_IN Core JavaScript Engine: J tcampbell RESO FIXE 2017-05-03
1338347 Telemetry measures for Compositor Frame Throughput (Scrolling/Animation) Core Graphics kats RESO FIXE 2018-10-15
1338595 [meta] Stop janking the browser UI Core DOM: Core & HTML nobody NEW --- 2020-04-30
1338802 CrossCompartmentWrapper handling is slow on Google Spreadsheet Core JavaScript Engine nobody NEW --- 2020-04-12
1339480 SessionStore causes long pauses on the parent process main thread Firefox Session Restore wiwang RESO DUPL 2017-03-30
1339543 PBrowser::Msg_RequestNativeKeyBindings is too slow Core DOM: Events masayuki RESO FIXE 2017-07-06
1339557 [Meta] Quantum Release Criteria: Figure out why we are so slow on Speedometer v2 Core JavaScript Engine nobody NEW --- 2019-07-12
1339593 Long GC pauses in Speedometer Core JavaScript: GC nobody RESO INVA 2017-06-08
1339758 Accessing offsetX/offsetY on MouseEvents dispatched from click() is slower than in other engines Core DOM: Core & HTML bugs RESO FIXE 2019-03-13
1340134 Telemetry probes using TOPIC_CYCLE_COLLECTOR_BEGIN may take more time than the CC slice itself Core XPCOM ericrahm+bz RESO FIXE 2017-07-02
1340842 Instrument tab closing time from click to tab being gone Toolkit Performance Monitori mconley RESO FIXE 2020-11-18
1341071 Fix Ion IC post write barriers Core JavaScript Engine: J jdemooij RESO FIXE 2017-03-14
1341531 Measure input event to event dispatcher (handler) Toolkit Performance Monitori legnaleurc RESO FIXE 2017-03-25
1341532 Measure paint request to display latency Toolkit Performance Monitori legnaleurc RESO INAC 2019-07-23
1341716 Walking the stack incorrectly in the profiler makes us show a call to Preferences::GetBool from Exception::Initialize Core Gecko Profiler nobody NEW --- 2017-10-06
1341750 Speed up reflows Core Layout nobody NEW --- 2019-09-17
1341768 input.selectionStart is slower than in Chrome/Safari Core DOM: Core & HTML bzbarsky RESO FIXE 2019-03-13
1341882 Slow performance at drawing rectangles on Google Slides Core Graphics nobody NEW --- 2018-08-22
1341900 WriteStructuredClone can be slow on Google Drive Core JavaScript Engine nobody REOP --- 2018-09-24
1341902 js::Stringify can be really slow on Google Drive Core JavaScript Engine nobody RESO FIXE 2018-05-15
1341913 Stop looking up GLContext symbols for every new window Core Graphics nobody NEW --- 2018-04-23
1342009 A fast path for BuildDisplayListForChild() improves more than 20% of time. Core Web Painting thinker.li RESO FIXE 2018-10-14
1342050 Shrink Promise instances from 8 to 4 slots Core JavaScript: Standard till RESO FIXE 2017-08-27
1342220 Janky Twitter thread-dismissing animation Core Layout dholbert RESO FIXE 2017-07-13
1342333 Remove any use of nsIURLClassifier.classifyLocalWithTables on the main thread Toolkit Safe Browsing nobody RESO DUPL 2019-01-07
1342632 Speed up PHttpChannelConstructor and consider streaming HttpChannelOpenArgs Core Networking: HTTP nobody NEW --- 2020-10-30
1342713 Optimize scrolling on Google Spreadsheets Core General nobody NEW --- 2018-11-25
1342714 Eliminate the cost of performance monitoring (js::AutoStopwatch) from scrolling google spreadsheets Toolkit Performance Monitori D.O.Teller+bugspam RESO FIXE 2017-03-29
1342951 Expensive sync reflows when holding the down key on google presentations Core SVG jwatt RESO FIXE 2017-10-02
1343005 Optimize `Quote` in json.cpp Core JavaScript Engine chiovolonit RESO FIXE 2017-08-26
1343158 Unable to get meaningful stack traces from async functions Core JavaScript Engine arai.unmht RESO FIXE 2017-04-17
1343383 nsIDOMWindowUtils::StartFrameTimeRecording should not use sync IPC Core Graphics: Layers mstange.moz ASSI --- 2018-03-05
1343425 Support asyncClassifyLocal in content process Toolkit Safe Browsing hchang.mozilla RESO FIXE 2017-04-11
1343490 Firefox (new versions) visible slower than older versions Firefox Untriaged nobody RESO INCO 2017-08-07
1343538 Overpainting on Google docs Core Web Painting nobody NEW --- 2019-01-10
1343588 [Meta] Make Facebook benchmark fast Core JavaScript Engine nobody NEW --- 2019-06-21
1343728 Stop doing sync IPC for PContent::Msg_CreateWindow Core DOM: Core & HTML nika RESO FIXE 2019-03-13
1344003 [meta] Create (or resurrect) BHR dashboard Data Platform and To Telemetry Dashboards dothayer RESO FIXE 2018-10-24
1344216 [meta] Stop doing sync IPC for WebVR Core WebVR kearwood RESO FIXE 2017-05-31
1344302 [meta] Tab closing performance Firefox Tabbed Browser mconley NEW --- 2021-04-30
1344377 Jank with unnecessary frame reconstruction & layout, when tweaking "position" on root of deeply-nested frame tree Core Layout nobody NEW --- 2018-01-23
1344398 Jank from frame reconstruction & layout, when tweaking "overflow" on root of deeply-nested frame tree Core Layout dholbert RESO FIXE 2017-08-25
1344469 Optimize Object.hasOwnProperty Core JavaScript Engine evilpies RESO FIXE 2018-09-14
1344751 optimize URL() read access in Worker threads for common URL schemes Core DOM: Workers catalin.badea392 RESO FIXE 2017-07-25
1344893 Report Navigation Timing into Telemetry Toolkit Performance Monitori legnaleurc RESO FIXE 2019-09-16
1345058 Use nsIURLClassifier.asyncClassifyLocalWithTables in nsDocument::PrincipalFlashClassification Toolkit Safe Browsing tnguyen RESO FIXE 2017-09-06
1345315 _handleTabTelemetryEnd can be too expensive Firefox Tabbed Browser dao+bmo RESO FIXE 2017-04-19
1345497 Remove the unused PVRManager::GetControllers sync IPC Core Graphics ehsan.akhgari RESO FIXE 2017-03-14
1345540 Measure input event handler to paint request latency Toolkit Performance Monitori legnaleurc RESO FIXE 2018-07-18
1345564 Remove PVRManager::GetImmediateSensorState sync IPC call and related code Core WebVR kearwood RESO FIXE 2017-03-14
1345633 IRC Cloud + Lastpass results in 5-20 second janks Firefox Extension Compatibil nobody RESO FIXE 2017-08-14
1345703 [meta] Byte stream-specialized tokenizer Core JavaScript Engine jwalden RESO DUPL 2017-11-28
1345706 [meta] Improve lazy parsing Core JavaScript Engine nobody NEW --- 2018-04-16
1346122 TIME_TO_NON_BLANK_PAINT_MS expired in 55 Toolkit Performance Monitori mstange.moz RESO FIXE 2017-03-16
1346178 Consider compiling Ion IC code less eagerly Core JavaScript Engine: J nobody NEW --- 2021-03-17
1346189 Inline AddSlot in Ion based on BaselineInspector Core JavaScript Engine: J nobody RESO WONT 2020-09-26
1346217 Optimize adding/defining new properties on native objects Core JavaScript Engine jdemooij RESO FIXE 2017-09-01
1346335 Is "new" LinkedIn incompatible with "new" Firefox? (Gecko Profiler overhead) Core JavaScript Engine: J nobody NEW --- 2019-06-21
1346365 Tab switching on GMail is slow due to texture allocation on Mac Core Graphics nobody NEW --- 2019-06-21
1346415 We need more native stacks from BHR Core XPCOM nika RESO FIXE 2017-05-11
1346583 Remove the PContent::Msg_OpenAnonymousTemporaryFile sync IPC Core DOM: Core & HTML ehsan.akhgari RESO FIXE 2019-03-13
1346723 [Meta] Setting input.value when input has focus is 1.1x slower than Chrome/Safari Core DOM: Core & HTML masayuki NEW --- 2020-12-14
1346854 GCLI starts network listeners for seemingly no reason DevTools Graveyard Graphic Commandline jryans RESO FIXE 2018-09-24
1346923 Change PVRManager::GetDisplays to async Core WebVR kearwood RESO FIXE 2017-03-20
1346926 Make PVRManager::SetHaveEventListener async Core WebVR kearwood RESO FIXE 2017-03-22
1346927 Replace PVRManager::GetSensorState with lock-free shared memory structure (Eliminating message queue IPC) Core WebVR kearwood NEW --- 2017-10-26
1346987 Remove two of the consumers of the PContent::Msg_OpenAnonymousTemporaryFile sync IPC message Core DOM: Core & HTML ehsan.akhgari RESO FIXE 2019-03-13
1347031 Move the MediaCache off of opening its temporary file fd synchronously in the content process Core Audio/Video: Playbac chris RESO FIXE 2017-03-23
1347035 Remove PBrowser::Msg_GetMaxTouchPoints Core DOM: Core & HTML ehsan.akhgari RESO FIXE 2019-07-17
1347369 Avoid dynamic allocation of URLParams in OriginAttributes methods Core DOM: Core & HTML ehsan.akhgari RESO FIXE 2019-03-13
1347376 [meta] Triggering image loads should be faster Core DOM: Core & HTML nobody RESO FIXE 2019-03-13
1347379 nsLoadGroup::Init() can be too slow Core Networking ehsan.akhgari RESO FIXE 2017-03-16
1347425 navigator.userAgent can do sync IPC Core DOM: Core & HTML ehsan.akhgari RESO FIXE 2019-03-13
1347489 Vector in StringSegmentRange should have some inline capacity Core JavaScript Engine jdemooij RESO FIXE 2017-03-15
1347525 Setting innerHTML slower than in Chrome Core DOM: Core & HTML nobody RESO FIXE 2019-03-13
1347666 Huff Post page load CPU usage much higher in Nightly vs 45 ESR Core General nobody NEW --- 2021-04-17
1347737 nsHtml5HtmlAttributes::clear spends a bunch of time deallocating Core DOM: HTML Parser hsivonen RESO FIXE 2017-08-16
1347824 [Meta] Make JS Parsing faster Core JavaScript Engine nobody NEW --- 2019-03-05
1347861 Consider storing hints during syntax parse Core JavaScript Engine nobody NEW --- 2018-02-27
1348053 Channel loading content for click-to-play media should be marked as urgent-start Core Audio/Video: Playbac suro001 RESO FIXE 2017-04-21
1348073 Consider enabling lazy frame construction for editable regions Core Layout m_kato RESO FIXE 2017-08-29
1348099 DOM Xrays should be able to cache a property not being present Core XPConnect janus926 RESO FIXE 2017-07-05
1348134 ScriptSource compression is often wasteful Core JavaScript Engine shu RESO FIXE 2017-04-17
1348278 Speculatively connect on mousedown on links Core Networking u408661 RESO FIXE 2017-08-25
1348280 Thumbnail causes jank on sites with a requestAnimationFrame Firefox New Tab Page ksteuber RESO FIXE 2017-09-05
1348361 Remove sync IPC when launching a child process Core IPC alex.gaynor RESO FIXE 2018-06-27
1348401 Make the PPrinting::ShowProgress IPDL method async Toolkit Printing nika RESO FIXE 2017-05-20
1348469 Consider using FramePropertyTable less in layout Core Layout mats NEW --- 2021-04-21
1348591 BufferList overhead is too high Core IPC hchang.mozilla RESO FIXE 2017-07-14
1348697 Optimize away OverflowAreasProperty more often Core Layout mats NEW --- 2019-12-27
1348772 Optimize Array.prototype.shift to be O(1) instead of O(n) Core JavaScript Engine jdemooij RESO FIXE 2020-01-22
1348850 Add an IC stub for adding the first expando property to unboxed objects Core JavaScript Engine: J nobody RESO INVA 2019-10-14
1349148 Improve performance of megamorphic stubs Core JavaScript Engine: J dpalmeiro NEW --- 2020-06-21
1349255 sending NotifyIMEFocus IPC messages can jank the browser Core DOM: Core & HTML freesamael RESO FIXE 2020-01-14
1349447 [meta] QF - Frameworks Core General nobody NEW --- 2019-07-29
1349448 [meta] QF - EmberJS Core General nobody NEW --- 2019-07-29
1349696 80ms rasterizes scrolling new linkedin profile page Core Graphics nobody RESO WORK 2018-11-13
1349750 APZ: Avoid blocking on the main thread to initiate APZ scrollbar dragging Core Panning and Zooming botond RESO FIXE 2017-09-25
1349809 getElevationRequired janks the parent process by doing IO on the main thread Toolkit Application Update nobody NEW --- 2020-12-14
1349822 [meta] updateCurrentBrowser can be slow Firefox Tabbed Browser nobody NEW --- 2020-07-28
1349924 Inline through polymorphic wrapper functions Core JavaScript Engine: J bhackett1024 REOP --- 2020-01-04
1350263 Port Baseline TypeOf IC to CacheIR Core JavaScript Engine: J evilpies RESO FIXE 2017-05-05
1350367 Make service worker ScriptLoader paths use cached js bytecode from cache API Core DOM: Service Workers nobody NEW --- 2018-11-05
1350412 Ensure that compositor thread BHR data is submitted to telemetry Core IPC nika RESO WORK 2017-05-23
1350417 Sync11Service.sync() can take a long time Firefox Sync nobody RESO INVA 2018-09-24
1350544 appcache does mainthread I/O Core Networking: HTTP nobody RESO INAC 2021-05-10
1350612 dbg.onNewGlobalObject can be too slow even when Debugger in NOT enabled Core JavaScript Engine jimb RESO WORK 2017-07-31
1350613 js::intl_patternForSkeleton() is very alloc heavy Core JavaScript Engine eoger RESO FIXE 2017-04-18
1350618 Bad performance on Sony Horizon game page Core Audio/Video: Playbac nobody NEW --- 2017-10-06
1350633 Remove the PBrowser::Msg_GetWidgetNativeData sync IPC Core Plug-ins nika RESO FIXE 2017-06-29
1350634 The PCompositorBridge::Msg_PLayerTransactionConstructor sync IPC is extremely inefficient Core Graphics: Layers dvander RESO FIXE 2017-05-09
1350635 PGPU::Msg_AddLayerTreeIdMapping sync IPC is extremely inefficient Core Graphics: Layers nobody RESO FIXE 2017-05-08
1350636 Remove the sync IPC used to set the dictionary used by the spelling checker (PRemoteSpellcheckEngine::Msg_SetDictionary) Core Spelling checker nobody RESO WONT 2017-05-11
1350637 Move LocalStorage from PContent-managed PStorage to PBackground-managed PBackgroundStorage (was: PStorage::Msg_Preload sync IPC takes too long) Core DOM: Core & HTML jvarga RESO FIXE 2019-03-13
1350638 Eliminate the PCompositorBridge::Msg_GetCompositorOptions sync IPC Core Graphics: Layers kats RESO FIXE 2017-04-10
1350640 Eliminate the PContent::Msg_GetBlocklistState sync IPC Core Plug-ins kyle RESO FIXE 2017-07-19
1350642 Remove the PBrowser::Msg_GetTabCount sync IPC Core DOM: Core & HTML mrbkap RESO FIXE 2019-03-13
1350643 Remove the PBrowser::Msg_GetDPI sync IPC Core DOM: Core & HTML freesamael RESO FIXE 2019-03-13
1350644 Remove the PBlob::Msg_WaitForSliceCreation sync IPC Core DOM: Core & HTML amarchesini RESO DUPL 2019-03-13
1350645 [meta] Migrate away from soon to be removed SDK modules in DevTools DevTools General nobody RESO FIXE 2018-06-13
1350646 Remove UI, extension, and child_process modules Add-on SDK Graveyard General kmaglione+bmo RESO FIXE 2017-08-24
1350745 satchelFormListener's prefs observer is very expensive Toolkit Form Manager nobody RESO DUPL 2017-04-26
1350749 Add some instrumentation to find commonly added preference observers Core General nobody NEW --- 2017-10-06
1350765 Calling TelemetryHistogram::Accumulate() even by HistogramID goes through hashtable lookup Toolkit Telemetry chutten RESO DUPL 2017-06-20
1350885 Consider de-virtualizing nsIDocument::Begin/EndUpdate Core DOM: Core & HTML bugs RESO WONT 2019-03-13
1351107 Make TokenStream parse both single-byte UTF- and two-byte source text Core JavaScript Engine jwalden RESO FIXE 2019-04-14
1351231 Implement PFetch protocol and backing FetchService to allow Workers to request fetches without involving the main thread of their process Core DOM: Networking ytausky ASSI --- 2021-05-21
1351313 Reuse nsDisplayText for frames Core Web Painting u459114 RESO WONT 2017-08-16
1351490 Only run plugin finding/init on flash and pdf MIME types Core Plug-ins kyle RESO FIXE 2017-04-13
1351733 Youtube settings widget is janky when playing fullscreen video Core Graphics mchang RESO FIXE 2017-04-18
1351769 Meta: Quantum Flow JS Changes Meta-Bug Core JavaScript: GC nobody NEW --- 2019-05-22
1351789 Add Telemetry probes for measuring garbage volume per GC Core JavaScript: GC nobody NEW --- 2018-03-07
1351790 Add hook to allow browser to interrupt GC Core JavaScript: GC sphink RESO WONT 2018-07-12
1351829 Consider faster alternatives to PLDHashTable in hot Layout code paths Core Layout nobody NEW --- 2018-11-26
1351830 Consider adding StyleDisplay() values to nsIFrame Core Layout nobody NEW --- 2018-08-31
1351857 nsHtml5ElementName::elementNameByBuffer and nsHTML5AttributeName::nameByBuffer are too slow Core DOM: HTML Parser nobody RESO FIXE 2017-07-20
1351924 Use nsChangeHint_UpdateComputedBSize to properly set the IsBResize() flag on reflow input Core Layout dbaron RESO FIXE 2019-12-24
1352078 Odd sliding of potential new LinkedIn connections (doesn't happen in Chrome) Core Layout nobody RESO WORK 2017-06-09
1352204 Only allow webextension and MPC=true (which=no shims) add-ons on Nightly Toolkit Add-ons Manager andrew.swan VERI FIXE 2017-10-04
1352205 Avoid running the refresh driver when the page is in background Core Layout nobody NEW --- 2021-02-18
1352442 Do not needlessly clear the compositor background before drawing Core Graphics: Layers bas RESO FIXE 2017-04-20
1352486 Improve performance on EmberPerf benchmark Core JavaScript Engine nobody NEW --- 2018-03-01
1352499 [meta] Retain and incrementally update display lists Core Web Painting matt.woodrow RESO FIXE 2019-06-03
1352501 Remove Reader Mode feature promotion panel Toolkit Reader Mode mconley VERI FIXE 2017-07-06
1352524 [meta] Improve GC scheduling Core JavaScript: GC jcoppeard NEW --- 2021-04-28
1352527 Put BidiPresUtils on a malloc/free diet Core Layout ehsan.akhgari RESO FIXE 2017-04-14
1352528 can we cache the results of gfxFontShaper::GetRoundOffsetsToPixels Core Graphics: Text jfkthame RESO FIXE 2017-04-12
1352531 can mozilla::dom::FontFaceSet::FindOrCreateUserFontEntryFromFontFace be faster? Core DOM: CSS Object Mode cam RESO FIXE 2018-04-06
1352684 On Windows we hit the registry for mimetype info for many ScriptLoaderRunnable and nsScriptloader::StartLoad requests loading a js or jsm file from file:/ Core DOM: Core & HTML nika RESO FIXE 2019-03-13
1352882 TextEditor should cache nsIDocumentEncoder it uses for OutputToString/Stream Core DOM: Editor m_kato RESO FIXE 2017-04-26
1352889 Ensure that PLDHashTable's second hash doesn't have padding with 0 bits for tables with capacity larger than 2^16 Core XPCOM dbaron RESO FIXE 2017-06-06
1352978 nsHTML5AttributeName::nameByBuffer allocates too often Core DOM: HTML Parser nobody RESO FIXE 2017-05-09
1353005 Get rid of sdk/content/mod in the highlighters DevTools Inspector zer0 RESO FIXE 2018-06-13
1353029 PDFjs should stop using sync messaging to check if it's enabled, and propagate that state asynchronously from the parent to the child instead Firefox PDF Viewer dothayer RESO FIXE 2020-01-13
1353060 Remote <browser>s are not visible as children of XUL <popup>s Core Graphics: Layers kmaglione+bmo RESO FIXE 2020-06-24
1353206 expose requestIdleCallback (or similar) API to non-DOM JS execution contexts Core XPConnect afarre RESO FIXE 2017-06-15
1353292 Transferring ArrayBuffers to/from a WebWorker has very poor performance for large ArrayBuffer sizes. Core JavaScript: GC nobody RESO FIXE 2017-10-06
1353359 Port BindName IC to CacheIR Core JavaScript Engine: J jdemooij RESO FIXE 2017-04-15
1353384 Optimize GetName TypeOfNoProperty Core JavaScript Engine: J nobody NEW --- 2019-12-29
1353440 Add a Background Hang Reporter for user interactivity periods Core DOM: Core & HTML nika RESO FIXE 2019-03-13
1353542 Switch to async/await from Task.jsm/yield Toolkit Async Tooling florian RESO FIXE 2018-04-07
1353586 _saveStateAsync shouldn't pile up on existing jank Firefox Session Restore wiwang ASSI --- 2018-10-30
1353656 Stop using sdk/system/child_process/subprocess in WebIDE DevTools Graveyard WebIDE poirot.alex RESO FIXE 2020-01-21
1353725 [meta] displaying the awesomebar panel could be smoother Firefox Address Bar nobody RESO INCO 2020-11-04
1353731 Too much time spent by osfile_async_front.jsm calling restartTimer / setTimeout (from Timer.jsm) Toolkit OS.File kanru RESO FIXE 2017-06-29
1353853 nsUrlClassifierDBService::BuildTables should use cached preferences Toolkit Safe Browsing tnguyen RESO FIXE 2017-04-21
1353956 mozilla::safebrowsing::LookupCacheV4::VerifyChecksum consumes >400ms of CPU during startup Toolkit Safe Browsing dlee RESO FIXE 2019-05-23
1354043 Chat window on Facebook takes long to open on initial click Core DOM: Core & HTML nobody RESO WORK 2019-03-13
1354080 Excessive CPU usage while the connecting/loading spinners are showing Core DOM: Content Process mconley RESO FIXE 2017-04-17
1354143 JumpListBuilder::CommitListBuild does main thread IO Firefox Shell Integration legnaleurc RESO FIXE 2017-07-05
1354389 MediaCache::Update() on the main thread can be blocked by I/O on a non-main thread Core Audio/Video: Playbac suro001 RESO FIXE 2017-11-23
1354455 Intermittent Assertion failure: mEventQueue.IsEmpty() || (needResumeOnOtherThread || mSuspended || !!mForcedCount), at ChannelEventQueue.cpp:91 Core Networking polo.hellfire RESO FIXE 2017-09-06
1354616 Removing timers (due to firing or cancellation) can be really slow) Core XPCOM bzbarsky RESO FIXE 2017-05-04
1354641 Adjust the heuristic in mozInlineSpellChecker to break the work to smaller chunks Core Spelling checker jj.evelyn RESO FIXE 2021-03-17
1354913 Animated GIFs and animated PNGs tick the refresh driver even when they are hidden in a XUL deck Core Graphics whawkins RESO FIXE 2019-05-09
1354943 Overpainting on Youtube channel page when scrolling down Core Web Painting nobody RESO WONT 2017-05-23
1354945 Initialize sandbox global properties lazily Core XPConnect nobody NEW --- 2018-11-05
1354956 TooltipTextProvider can cause synchronous reflow when computing element direction Toolkit General enndeakin RESO FIXE 2017-05-10
1355346 CocoaFileUtils::AddOriginMetadataToFile() called at the end of file downloads can do sync IPC on the main thread Toolkit Downloads API mconley RESO FIXE 2019-10-09
1355416 Long composition times with Google blog on Windows coming from GetDeviceRemovedReason Core Graphics bas RESO WONT 2021-05-18
1355419 Compositor took time because of GetDeviceRemovedReason calls Core Graphics: Layers nobody RESO DUPL 2017-04-11
1355456 Investigate preparing the next tab on mousedown on the tab close button Firefox Tabbed Browser nobody NEW --- 2019-03-09
1355466 Activating the browser window is janky Core Widget: Cocoa nobody NEW --- 2019-01-04
1355472 [meta] Speedometer backbone.js footer updating code is slower than in Chrome/Safari Core DOM: Core & HTML nobody NEW --- 2020-04-12
1355548 WheelTransaction::GetTimeoutTime() should probably use cached preference value Core DOM: Events stone123456 RESO FIXE 2017-05-25
1355566 Profiler leaks data with DEBUG build, causes shutdown crash or leaks Core Gecko Profiler mstange.moz RESO FIXE 2018-02-12
1355595 Simplify the default font size calculation for the spellchecker underline Core Layout jj.evelyn RESO FIXE 2017-08-02
1355600 nsFont destructor takes 9ms to free up memory. Core Layout nobody RESO DUPL 2017-07-24
1355746 Parser should use idle dispatch and not a timer for background tabs Core DOM: HTML Parser hchang.mozilla RESO FIXE 2017-08-08
1356070 https://doc.servo.org/webrender/ hangs the main thread Core JavaScript Engine: J nobody RESO DUPL 2017-04-21
1356211 Supports custom callback thread for nsIURILCassifier.asyncClassifyLocalWithTables Toolkit Safe Browsing hchang.mozilla RESO WONT 2017-05-09
1356317 Support remote layer trees in popups on Windows Core Graphics: Layers spohl.mozilla.bugs VERI FIXE 2018-04-15
1356334 Add UI for flagging long running Web Extension scripts and provide the option to stop them WebExtensions Frontend kmaglione+bmo RESO FIXE 2018-06-19
1356533 Excessive CPU usage by the content process (racing the refresh driver?) on eBay product page Core DOM: Core & HTML tschneider RESO WORK 2019-03-13
1356546 Avoid repeated structured clones when transporting add-on messages WebExtensions General kmaglione+bmo RESO FIXE 2018-06-19
1356652 Consider updating our PGO training set Firefox Build System General away RESO FIXE 2020-09-23
1356654 Investigate performance from VS2017's new optimizer Firefox Build System General nobody RESO FIXE 2018-03-02
1356662 1.2ms uninterruptible reflow at get_scrollClientRect@chrome://global/content/bindings/scrollbox.xml:131:18 Toolkit XUL Widgets nobody RESO DUPL 2017-08-17
1356670 26ms uninterruptible reflow at _adjustContainerHeight@chrome://browser/content/customizableui/panelUI.xml:382:15 Firefox Menus nobody RESO DUPL 2017-06-16
1356674 32ms uninterruptible reflow at get_alignmentPosition@chrome://global/content/bindings/popup.xml:158:11 Toolkit XUL Widgets enndeakin RESO FIXE 2017-10-04
1356686 OMT brotli decompression Core Networking: HTTP nobody NEW --- 2021-05-03
1356687 6.3ms uninterruptible reflow at _updateTabsVisibilityStatus@chrome://browser/content/tabbrowser.xml:7516:1 Firefox Tabbed Browser nobody RESO WONT 2017-04-21
1356694 Profile capture fails with MOZ_PROFILER_STARTUP=1 Core Gecko Profiler n.nethercote RESO FIXE 2017-04-24
1356705 28ms uninterruptible reflow at set_scrollPosition@chrome://global/content/bindings/scrollbox.xml:207:13 Toolkit XUL Widgets mconley VERI FIXE 2020-05-13
1356763 4.8ms uninterruptible reflow at ensureElementIsVisible@chrome://global/content/bindings/richlistbox.xml:208:30 Firefox Address Bar tnguyen RESO FIXE 2017-07-13
1356765 6.9ms uninterruptible reflow at onxblpopupshowing@chrome://global/content/bindings/popup.xml:268:1 Toolkit XUL Widgets nobody NEW --- 2020-12-14
1356825 [meta] AddonManager startup is too slow Toolkit Add-ons Manager nobody NEW --- 2020-08-28
1356858 1.8ms uninterruptible reflow at openLinkIn@chrome://browser/content/utilityOverlay.js:472:5 Firefox Tabbed Browser nobody RESO FIXE 2017-06-08
1356862 1.2ms uninterruptible reflow at setDefaultFocus@resource://gre/modules/CommonDialog.jsm:246:17 Toolkit General nobody RESO INCO 2017-11-28
1356920 Refactor tabs in title bar implementation to avoid JS layout calculations Firefox Theme mconley RESO FIXE 2020-05-11
1357054 2.15ms uninterruptible reflow at _rebuild@chrome://browser/content/search/search.xml:1540:15 Firefox Search nobody RESO INCO 2020-01-06
1357114 WindowsJumpLists.jsm refreshes itself every 2 minutes or so via a timer, kicking off a Places query and a list building activity that can cause us to skip a frame Firefox General wiwang RESO FIXE 2018-05-14
1357146 Attempting to set Firefox as default browser results in an nsITimer firing every second for up to 10 minutes Firefox General dlee VERI FIXE 2017-08-08
1357154 If about:preferences is open on Windows, it will poll the OS to see if the default browser has changed every second Firefox Preferences me RESO FIXE 2017-07-07
1357180 Get some real world data on what JS built-ins web pages use in the wild Core JavaScript Engine kvijayan RESO FIXE 2019-05-22
1357183 Measure GC slice overhead Core JavaScript: GC nobody RESO INVA 2017-05-16
1357196 Do not synchronously wait for background sweep thread during GC Core JavaScript: GC nobody RESO WORK 2017-05-10
1357481 1.03ms uninterruptible reflow at appendPrompt@chrome://browser/content/browser.js:8426:5 Firefox General nobody NEW --- 2018-03-19
1357486 Turn on OOP extensions by default on Windows WebExtensions General kmaglione+bmo RESO FIXE 2018-06-19
1357487 Turn on OOP extensions by default on Linux WebExtensions General kmaglione+bmo VERI FIXE 2019-06-23
1357571 Youtube settings widget is still janky when playing fullscreen video Core Graphics nobody NEW --- 2018-01-22
1357621 Amazon.com search results page sync reflows are super expensive in Gecko Core Layout jfkthame RESO WORK 2017-08-07
1357638 "dom.forms.inputmode" is referred with Preferences::GetBool() at every click in <input type="text"> and <textarea> and moving focus to them Core DOM: UI Events & Foc ben.tian RESO FIXE 2019-03-13
1357645 Consider a faster path that uses preparsed attributes in nsGenericHTMLElement::CopyInnerTo Core DOM: Core & HTML ksteuber RESO FIXE 2019-03-13
1357680 Babel class inheritance code confuses TI and Ion inlining Core JavaScript Engine: J jdemooij RESO FIXE 2019-04-30
1357756 1.07ms uninterruptible reflow at open@resource://gre/modules/SelectParentHelper.jsm:109:24 Firefox General nobody NEW --- 2019-10-11
1357810 Investigate source of memory_pressure event in gecko, and whether to repurpose it Core JavaScript: GC nobody NEW --- 2019-02-12
1357813 Add a "GC Exclusion" mode which suppresses expensive GCs Core JavaScript: GC nobody RESO DUPL 2018-05-17
1357862 [meta] Support multiple globals per compartment (same-compartment realms) Core JavaScript Engine jdemooij RESO FIXE 2019-06-18
1357882 BaselineJIT: Pre-compile the most commonly used self-hosted functions Core JavaScript Engine: J nobody RESO DUPL 2019-05-23
1357884 Pre-generate and cache the most common optimized Baseline IC stubs Core JavaScript Engine: J kvijayan NEW --- 2018-02-15
1358291 LinkedIn loads 2+ sec slower on Firefox compared to Chrome Core General nobody RESO WORK 2018-07-03
1358369 nsExternalHelperAppService::GetTypeFromExtension() can do main thread IO Firefox File Handling nobody RESO DUPL 2017-05-04
1358387 1.02ms uninterruptible reflow at set_label@chrome://browser/content/tabbrowser.xml:7593:37 Firefox Tabbed Browser dao+bmo RESO FIXE 2017-05-30
1358388 1.03ms uninterruptible reflow at _moveItemsBackToTheirOrigin@resource:///modules/CustomizableUI.jsm:4203:1 Firefox Toolbars and Customi gijskruitbosch+bugs RESO FIXE 2018-05-01
1358390 1.24ms uninterruptible reflow at useLandscapeMode@chrome://devtools/content/inspector/inspector.js:460:27 DevTools Inspector nobody NEW --- 2018-06-13
1358391 2.24ms uninterruptible reflow at handleEvent@chrome://browser/content/tabbrowser.xml:6224:19 Firefox Tabbed Browser nobody RESO WORK 2017-11-28
1358397 1.48ms uninterruptible reflow at showLearn@chrome://browser/content/newtab/newTab.js:2613:5 Firefox New Tab Page nobody RESO WONT 2017-11-28
1358405 13.97ms uninterruptible reflow at getComputedURL@chrome://browser/content/nsContextMenu.js:979:15 Firefox Menus nobody NEW --- 2018-03-19
1358408 1.37ms uninterruptible reflow at BrowserOpenAddonsMgr/<@chrome://browser/content/browser.js:6577:7 Firefox Tabbed Browser nobody RESO INCO 2018-03-19
1358443 9.59ms uninterruptible reflow at adjustHeight@chrome://global/content/bindings/autocomplete.xml:1239:32 Toolkit Autocomplete gijskruitbosch+bugs RESO FIXE 2019-03-07
1358446 2.66ms uninterruptible reflow at _setMaxHeight@chrome://browser/content/customizableui/panelUI.xml:371:13 Firefox Toolbars and Customi nobody RESO WORK 2017-11-28
1358453 Throttle scrollbox scroll button disabled state updates while scrolling to avoid flushing layout Toolkit XUL Widgets dao+bmo RESO FIXE 2017-05-26
1358458 6.27ms uninterruptible reflow at _showNotification@chrome://global/content/bindings/notification.xml:270:17 Toolkit XUL Widgets nobody RESO INCO 2019-10-11
1358476 Add nsThread::idleDispatch(nsIRunnable, uint32_t aTimeout) Core DOM: Core & HTML afarre RESO FIXE 2019-03-13
1358495 Implement getComputedStyleWithoutFlushing or equivalent Core DOM: CSS Object Mode legnaleurc RESO WONT 2017-06-12
1358599 Use runtime checks for GC pre-barriers instead of patchable jumps Core JavaScript Engine: J kvijayan RESO FIXE 2017-05-02
1358606 Share Baseline jitcode for self-hosted functions across whole zone Core JavaScript Engine: J nobody RESO DUPL 2019-05-23
1358687 1.28ms uninterruptible reflow at _adjustFocusAfterTabSwitch@chrome://browser/content/tabbrowser.xml:1355:9 Firefox Tabbed Browser nobody RESO FIXE 2018-07-30
1358695 1.43ms uninterruptible reflow at focusContent@resource://gre/modules/RemoteFinder.jsm:169:5 Toolkit Find Toolbar nobody RESO WORK 2017-11-28
1358703 2.86ms uninterruptible reflow at _shiftMainView@chrome://browser/content/customizableui/panelUI.xml:272:30 Firefox Toolbars and Customi nobody RESO WORK 2017-11-28
1358712 uninterruptible reflow at _calcMouseTargetRect@chrome://browser/content/tabbrowser.xml:7697:27 when moving the mouse Firefox General mconley VERI FIXE 2018-11-23
1358719 1.26ms uninterruptible reflow at PT__updateChevronTimerCallback@chrome://browser/content/places/browserPlacesViews.js:1205:22 Firefox Bookmarks & History mconley RESO FIXE 2018-03-15
1358721 5.05ms uninterruptible reflow at adjustTabstrip@chrome://browser/content/tabbrowser.xml:5949:24 Firefox Tabbed Browser dao+bmo RESO FIXE 2017-05-31
1358722 1.43ms uninterruptible reflow at updateLWTStyling@resource:///modules/CustomizeMode.jsm:635:23 Firefox Toolbars and Customi nobody RESO DUPL 2018-03-20
1358724 1.15ms uninterruptible reflow at updateOverflowStatus@chrome://browser/content/places/browserPlacesViews.js:1163:1 Firefox Bookmarks & History nobody NEW --- 2018-03-26
1358727 1.00ms uninterruptible reflow at updateCurrentBrowser@chrome://browser/content/tabbrowser.xml:1265:17 Firefox Tabbed Browser nobody RESO FIXE 2017-06-08
1358728 1.14ms uninterruptible reflow at startFind@chrome://global/content/bindings/findbar.xml:1142:13 Toolkit Find Toolbar nobody RESO FIXE 2017-06-08
1358729 1.75ms uninterruptible reflow at onResize@chrome://devtools/content/sourceeditor/codemirror/codemirror.bundle.js:3783:1 DevTools Source Editor nobody NEW --- 2018-06-13
1358730 2.41ms uninterruptible reflow at stop@chrome://global/content/bindings/browser.xml:99:13 Firefox Tabbed Browser nobody NEW --- 2018-03-19
1358731 0.95ms uninterruptible reflow at removePrompt@chrome://browser/content/browser.js:8515:7 Firefox Tabbed Browser nobody RESO FIXE 2017-06-08
1358733 1.09ms uninterruptible reflow at _customizationEnding@chrome://browser/content/browser-customization.js:98:5 Firefox Toolbars and Customi nobody RESO FIXE 2017-06-08
1358734 0.93ms uninterruptible reflow at showNavToolbox@chrome://browser/content/browser-fullScreenAndPointerLock.js:576:18 Firefox Toolbars and Customi nobody NEW --- 2019-10-11
1358753 Allocate ProxyValueArray inline Core JavaScript Engine jdemooij RESO FIXE 2017-04-25
1358792 24.99ms uninterruptible reflow at adjustSiteIconStart@chrome://global/content/bindings/autocomplete.xml:2379:13 Toolkit Autocomplete paolo.mozmail RESO FIXE 2017-08-22
1358810 0.91ms uninterruptible reflow at create@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/framework/toolbox-hosts.js:86:5 DevTools General nobody NEW --- 2018-06-13
1358811 0.91ms uninterruptible reflow at ssi_undoCloseTab@resource:///modules/sessionstore/SessionStore.jsm:2429:5 Firefox Session Restore nobody RESO FIXE 2017-06-08
1358813 0.92ms uninterruptible reflow at select@chrome://global/content/bindings/textbox.xml:115:11 Firefox Tabbed Browser gijskruitbosch+bugs RESO FIXE 2018-10-19
1358815 0.90ms uninterruptible reflow at getFindBar@chrome://browser/content/tabbrowser.xml:178:11 Toolkit Find Toolbar gijskruitbosch+bugs RESO FIXE 2018-03-30
1358823 0.92ms uninterruptible reflow at updateBrowserRemoteness@chrome://browser/content/tabbrowser.xml:1795:15 Firefox Tabbed Browser nobody RESO FIXE 2017-06-08
1358829 0.99ms uninterruptible reflow at loadViewInternal@chrome://mozapps/content/extensions/extensions.js:932:5 Toolkit Add-ons Manager nobody REOP --- 2019-01-22
1358902 1.25ms uninterruptible reflow at detachController@chrome://global/content/bindings/autocomplete.xml:384:13 Firefox Address Bar nobody RESO WORK 2017-11-28
1358907 Telemetry shouldn't query the add-ons DB at startup Toolkit Telemetry andrew.swan RESO FIXE 2020-07-21
1358921 Avoid loading and initializing modules in BrowserGlue._finalUIStartup Firefox General kmaglione+bmo RESO FIXE 2017-06-01
1358927 Initializing gfxPlatform to get telemetry data is quite slow Core Graphics nobody REOP --- 2018-03-20
1358974 Profile and optimize Baseline compilation Core JavaScript Engine: J nobody NEW --- 2018-04-26
1359031 Don't trigger early search service init in Telemetry Toolkit Telemetry alessio.placitelli RESO FIXE 2017-05-25
1359259 0.92ms uninterruptible reflow at PopupNotifications_showPanel@resource://gre/modules/PopupNotifications.jsm:932:9 Toolkit Notifications and Al nobody NEW --- 2019-10-11
1359263 2.17ms uninterruptible reflow at receiveMessage@resource://gre/modules/SelectParentHelper.jsm:214:7 Core Layout: Form Control nobody NEW --- 2019-10-11
1359296 Terrible scrolling on Mega page, profile attached (Possibly NSFW) Core CSS Parsing and Comp nobody NEW --- 2017-10-06
1359384 nsXBLResourceLoader::NotifyBoundElements doesn't account for display: contents elements and may reframe unnecessarily. Core XBL emilio RESO FIXE 2017-04-28
1359400 Back button paint times significantly worse in Firefox Core General nobody RESO DUPL 2017-10-11
1359408 0.29ms uninterruptible reflow at _handleDOMChange@chrome://extensions/content/ext-browser-content.js:215:24 WebExtensions Frontend nobody NEW --- 2019-12-19
1359584 Stop FrameLayerBuilder from mutating display items Core Web Painting mikokm RESO FIXE 2019-03-12
1359653 Pre-load scripts needed during startup in a background thread Core XPConnect kmaglione+bmo RESO FIXE 2020-04-23
1359765 13.86ms uninterruptible reflow at close@chrome://browser/content/browser-fullScreenAndPointerLock.js:133:5 Firefox General nobody RESO FIXE 2017-06-08
1359851 Load SocialAPI providers lazily Firefox Graveyard SocialAPI mixedpuppy RESO FIXE 2019-02-25
1359855 Don't initialize devtools right after first window paint DevTools General poirot.alex RESO FIXE 2018-06-13
1359989 uninterruptible reflow at _openPanel@resource:///modules/UrlbarView.jsm Firefox General nobody RESO FIXE 2019-07-29
1359991 2.61ms uninterruptible reflow at onxblmousedown@chrome://browser/content/tabbrowser.xml:7392:11 Firefox Tabbed Browser enndeakin RESO FIXE 2017-10-04
1360028 0.99ms uninterruptible reflow at showNotification@chrome://browser/content/browser-addons.js:412:22 Firefox General nobody NEW --- 2018-03-05
1360043 1.57ms uninterruptible reflow at doFocus@chrome://global/content/bindings/popup.xml:334:13 Toolkit XUL Widgets nobody RESO FIXE 2017-06-08
1360078 1.13ms uninterruptible reflow at PopupNotifications_dismiss@resource://gre/modules/PopupNotifications.jsm:690:7 Firefox General nobody RESO FIXE 2017-06-08
1360164 The first async XHR done during startup blocks the main thread while initializing nsProtocolProxyService Core Networking daniel RESO DUPL 2017-06-21
1360167 WindowsUIUtils::GetInTabletMode blocks the UI thread during startup Core Widget: Win32 agashlin RESO FIXE 2017-08-16
1360171 UI spends too much time waiting for Direct3D 11 to initialize Core Graphics dvander RESO FIXE 2017-06-08
1360202 The first access to Services.cookies does main thread I/O to create the cookie database file Core Networking: Cookies nobody RESO DUPL 2017-05-16
1360205 Getting a profile lock takes a long time after an update Toolkit Startup and Profile nobody RESO WORK 2017-07-20
1360214 SanityTest.js is expensive during startup Core Graphics milaninbugzilla RESO FIXE 2017-06-15
1360215 3.72ms uninterruptible reflow at get_lineScrollAmount@chrome://global/content/bindings/scrollbox.xml:172:13 Toolkit XUL Widgets nobody RESO INCO 2019-10-11
1360261 GMPInstallManager causes jank off a timer in _delayedStartup Core Plug-ins dharvey RESO FIXE 2017-07-12
1360277 tp5 regression in November on windows 8 Core JavaScript Engine evilpies RESO WONT 2017-05-20
1360308 ExceptionHandler::WriteMinidumpForChild() can hang for a long time when generating a minidump Toolkit Crash Reporting cervantes.yu RESO FIXE 2018-11-26
1360328 Hangs during the network:link-status-changed event (with nsNotifyAddrListener::ChangeEvent::Run() on the stack) Core Networking valentin.gosu RESO FIXE 2017-05-18
1360406 Get rid of the contextmenu sync IPC Firefox Menus me RESO FIXE 2018-02-06
1360624 Cache calls to GetJitContext in compiler Core JavaScript Engine: J kvijayan NEW --- 2018-02-15
1360702 GetProcSelfSmapsPrivate() can be really slow (hurts users using test pilot really badly) Toolkit Telemetry nobody RESO FIXE 2017-08-08
1361067 coalesce mouse events to be once per refresh cycle (requestAnimationFrame, rAF) (preffed off) Core DOM: UI Events & Foc stone123456 RESO FIXE 2019-03-13
1361091 Can we avoid places main thread IO before the first window is shown? Firefox General nobody RESO DUPL 2019-02-20
1361095 Can nsContentPrefService avoid main thread IO before the first window is shown? Firefox General nobody NEW --- 2018-04-10
1361102 nsUpdateService.js does main thread IO writes for the update xml files during the first startup after an update, and whenever an update is downloaded Toolkit Application Update robert.strong.bugs RESO FIXE 2019-01-07
1361115 1.42ms uninterruptible reflow (sync layout flush) at onResize in tabprompts.jsm Firefox Tabbed Browser nobody NEW --- 2019-04-08
1361257 Don't synchronously flush rendering on Windows Core Graphics: Layers dvander RESO FIXE 2017-07-12
1361262 nsAppStartup::TrackStartupCrashEnd() can cause main-thread I/O and fflush() Toolkit Startup and Profile milaninbugzilla RESO FIXE 2020-09-11
1361322 Don't try to open the favicons database on startup for existing profiles Toolkit Places mak RESO FIXE 2017-06-15
1361461 Consider dispatching WindowDestroyedEvents to the idle queue Core DOM: Core & HTML ehsan.akhgari RESO FIXE 2019-03-13
1361500 UTCToLocalStandardOffsetSeconds blocks startup with main thread IO on Windows (calling _tzset) Core JavaScript Engine dothayer RESO FIXE 2017-07-07
1361622 MediaDecoder::Invalidate() may block the main thread for up to 8 seconds Core Audio/Video: Playbac nobody RESO WORK 2017-09-04
1361625 MediaCacheStream::NotifyDataReceived() may block the main thread for up to 8 seconds Core Audio/Video: Playbac nobody RESO FIXE 2019-05-15
1361635 1.19ms uninterruptible reflow from window.innerWidth at getContentSize@resource://gre/modules/PageThumbUtils.jsm:112:9 Core DOM: Core & HTML nobody NEW --- 2019-10-11
1361709 Consider doing FlushPendingLinkUpdatesFromRunnable as an idle callback, not a runnable Core DOM: Core & HTML ehsan.akhgari RESO FIXE 2019-03-13
1361900 Use script precompiler in content processes Core XPConnect kmaglione+bmo RESO FIXE 2017-08-07
1361918 TextureClient::TryReadLock() shows up a lot in the 8-second BHR hang data Core Graphics: Layers nobody NEW --- 2020-11-06
1362058 Further limit the amount of sessionStorage data we store and serialize Firefox Session Restore ttaubert RESO FIXE 2019-04-20
1362068 Amazon homepage start: loading home page is slow Core JavaScript Engine kvijayan RESO WORK 2018-09-11
1362094 Parent INPUT_EVENT_RESPONSE_MS p95 regressed from 16.3 to 18ms on 2017-04-05 build Core General nobody RESO INCO 2017-06-19
1362166 Enable IPDL timeout for communicating to the GPU process Core Graphics freesamael RESO FIXE 2017-07-13
1362212 Move MEDIA_CAN_CREATE_XX_DECODER telemetry to off-main-thread Core Audio/Video: Playbac chris RESO FIXE 2017-06-08
1362364 XPIProvider.jsm should not initialize NSS during early startup Core Security: PSM dtownsend RESO FIXE 2017-06-09
1362377 omni.ja vs ts_paint trade off Firefox Build System General catlee RESO FIXE 2018-12-27
1362382 ::RegisterDragDrop is expensive during startup Core Widget: Win32 ksteuber RESO FIXE 2019-08-01
1362401 PdfJs.init causes startup jank Firefox PDF Viewer ksteuber RESO DUPL 2017-09-07
1362412 foofighters.com is still slow to animate because of unnecessary invalidation for non-border-collapse tables Core Layout demo99 RESO FIXE 2018-05-28
1362533 1.0ms uninterruptible reflow at PT__onDragOver@chrome://browser/content/places/browserPlacesViews.js:1600:11 Firefox Bookmarks & History nobody NEW --- 2018-03-26
1362542 4.26ms uninterruptible reflow at _updateTabsVisibilityStatus@chrome://browser/content/tabbrowser.xml:7481:1 Firefox Tabbed Browser dao+bmo RESO FIXE 2017-05-30
1362569 1.21ms uninterruptible reflow at _lockTabSizing@chrome://browser/content/tabbrowser.xml:6073:17 Firefox Tabbed Browser mconley RESO FIXE 2018-07-21
1362586 Slow sync reflows when loading www.amazon.com Core Layout jfkthame RESO WORK 2017-08-07
1362625 Amazon back start: page navigation using back button is slow Core General nobody RESO DUPL 2017-07-21
1362626 The lock in ChannelEventQueue::RunOrEnqueue() can be contended Core Networking polo.hellfire RESO DUPL 2017-09-17
1362808 4.64ms uninterruptible reflow at onEntered@chrome://global/content/printUtils.js:669:7 Toolkit Printing nobody RESO FIXE 2017-06-08
1362987 CHECKERBOARD_DURATION regression on 2017-05-04 Core Panning and Zooming kmaglione+bmo RESO FIXE 2017-05-24
1363054 Make type monitor stubs work with unknown objects/values Core JavaScript Engine: J jdemooij RESO FIXE 2017-05-29
1363163 nsSoundPlayer::SoundReleaser::Run should not add to existing jank Core Widget: Win32 tnguyen RESO FIXE 2018-11-12
1363354 YouTube first video play is slow Core General nobody NEW --- 2017-10-06
1363383 Channel switching on Slack is slow Core JavaScript Engine nobody NEW --- 2021-04-26
1363384 nsZipArchive::GetDataOffset is expensive during startup Core Networking: JAR xeonchen RESO DUPL 2018-01-10
1363398 GetShellFolderPath is expensive during startup Toolkit Startup and Profile florian RESO FIXE 2017-06-12
1363399 Amazon back start: page navigation using back button is slow (dupe?) Core Layout nobody NEW --- 2017-10-06
1363403 Facebook profile navigation start: access the user photo profile from a post Core JavaScript Engine nobody NEW --- 2019-08-28
1363423 Extremely bad PresShell::Paint performance on http://a816-dohbesp.nyc.gov/IndicatorPublic/dognames/ Core Panning and Zooming botond RESO FIXE 2017-08-02
1363425 _migrateFromRDF causes main thread IO during startup Firefox File Handling nobody VERI WORK 2018-03-29
1363438 15% regression in several component speedometer tests around April 24 Core JavaScript Engine nobody RESO WORK 2021-03-15
1363482 Pre-load files needed during startup on a background thread Core General kmaglione+bmo RESO FIXE 2020-08-09
1363541 Permission Manager should not block the first window from painting Core Permission Manager amarchesini RESO FIXE 2020-07-13
1363586 [meta] Creating the XPCOM system info service is super expensive Core XPCOM nobody NEW --- 2020-04-02
1363695 Amazon search start: search result loading is slow Core Layout nobody RESO INCO 2019-02-21
1363805 Only flush styles on nsComputedDOMStyle::UpdateCurrentStyleSources if we know that the child or one of its ancestors need a restyle. Core CSS Parsing and Comp legnaleurc RESO FIXE 2017-09-30
1363829 consider using a single nsITimer for setTimeout() in windows Core DOM: Core & HTML ben RESO FIXE 2021-01-12
1363919 spend too much time getting frame properties in FrameLayerBuilder::GetPaintedLayerScale in order to snap scroll areas to layer pixels Core Layout jwatt RESO WORK 2017-09-07
1363922 spend too much time snapping scroll areas to layer pixels Core Layout bas RESO FIXE 2017-08-25
1363959 Consider atomizing the strings for the comparisons while resolving a property Core XPConnect janus926 RESO FIXE 2017-07-21
1363963 XrayTraits::getExpandoObject() could be done twice in a single js::Proxy::get() call Core XPConnect janus926 RESO FIXE 2017-06-02
1364018 Coalesce wheel events more aggressively Core DOM: UI Events & Foc bugs RESO FIXE 2019-03-13
1364091 Defer mozilla::widget::AudioSession::Start() until later in startup Core Widget: Win32 nobody NEW --- 2020-08-08
1364250 Move JAR channel I/O off of main thread where possible Core Networking: JAR nobody RESO DUPL 2017-08-17
1364290 1.89ms uninterruptible reflow at insertPlaceholder@resource://app/modules/DragPositionManager.jsm:181:7 Firefox Toolbars and Customi nobody NEW --- 2018-03-20
1364324 0.98ms uninterruptible reflow at AreaPositionManager@resource://app/modules/DragPositionManager.jsm:24:23 Firefox Toolbars and Customi nobody NEW --- 2018-03-19
1364360 0.96ms uninterruptible reflow at gotoPref@chrome://browser/content/preferences/in-content/preferences.js:195:3 Core DOM: Core & HTML bzbarsky RESO FIXE 2019-03-13
1364725 2.68ms uninterruptible reflow at updateLWTStyling@resource://app/modules/CustomizeMode.jsm:669:23 Firefox Toolbars and Customi nobody RESO DUPL 2017-05-23
1364815 Devirtualize do_QueryFrame() Core Layout mats RESO FIXE 2017-09-12
1364816 Object.getOwnPropertyNames(window) is slow Core DOM: Core & HTML bzbarsky RESO FIXE 2019-03-13
1364854 Optimize Object.assign Core JavaScript Engine jdemooij RESO FIXE 2019-05-27
1364861 Setting innerHTML slower than in Safari Core DOM: Core & HTML nobody NEW --- 2019-03-13
1364908 Support inlining functions that use arguments[x] Core JavaScript Engine: J nicolas.b.pierron RESO FIXE 2019-01-10
1364974 Allow off-thread decoding multiple scripts for a single global in one operation Core JavaScript Engine kmaglione+bmo RESO FIXE 2017-05-30
1365278 Many calls from gfxFont::GetShapedWord<..> to Telemetry::Accumulate Core Graphics: Text jfkthame RESO FIXE 2017-08-04
1365296 Create reference profiles for heavy users based on Telemetry data Toolkit Startup and Profile dstrohmeier RESO FIXE 2018-09-03
1365305 0.86ms uninterruptible reflow at _positionPinnedTabs@chrome://browser/content/tabbrowser.xml:6147:33 Firefox Tabbed Browser nobody NEW --- 2018-08-17
1365333 Firefox is very slow on Live Nation ticket finder, with APZ enabled Core Panning and Zooming botond RESO FIXE 2017-07-07
1365334 Parent INPUT_EVENT_RESPONSE_MS p95 regressed from 18.3 to 20.7ms on 2017-05-06 build Core General nobody RESO INCO 2017-06-19
1365361 Baseline: Optimize intrinsics used in self-hosted functions Core JavaScript Engine: J nobody NEW --- 2018-04-07
1365574 When opening devtools there is some heavy Promise usage in the parent process causing jank DevTools General poirot.alex RESO FIXE 2018-06-13
1365605 1.36ms uninterruptible reflow at _loadURL@chrome://browser/content/urlbarBindings.xml:593:11 Firefox Address Bar nobody RESO FIXE 2017-06-08
1365632 Multi-second main thread hangs in GC when visiting Twitch.tv (and maybe cbc.ca) Core JavaScript: GC nobody RESO WORK 2017-10-16
1365719 Collect a telemetry probe for how long we spend processing sync IPC messages Core IPC nika RESO FIXE 2017-06-05
1365776 gfxDWriteFont::MeasureGlyphWidth() can be really slow Core Graphics: Text jfkthame RESO FIXE 2017-06-19
1365783 Deleting frames under nsCSSFrameConstructor::ContentRemoved() can be really expensive Core Layout jwatt RESO FIXE 2017-08-30
1365793 JSONParser::readString() is slower than it needs to be on Windows because of isxdigit() Core JavaScript Engine ehsan.akhgari RESO FIXE 2017-05-19
1365794 YouTube: Investigate rasterization times for bug 1363335 Core Graphics lsalzman RESO FIXE 2017-07-27
1365823 tab switching to gmail with theme is very slow on mac Core Graphics nobody NEW --- 2017-11-27
1365830 Make nsGlobalWindow::ScrollTo avoid flushing layout for (0, 0) Core DOM: Core & HTML ehsan.akhgari RESO FIXE 2019-03-13
1365835 Lots of time spent in createScriptForLazilyInterpretedFunction() when playing a youtube video Core JavaScript Engine sstangl NEW --- 2018-03-05
1365853 Performance is poor loading booking data from eversports.at Firefox Untriaged nobody RESO WORK 2017-12-05
1365970 Move sessionrestore data collector timer in the content process to idle dispatch Firefox Session Restore wiwang RESO FIXE 2018-05-14
1365982 Attach FrameProperties to each frame instead of using a shared hashtable Core Layout jfkthame RESO FIXE 2020-08-29
1366030 [meta] Win64 profiler/stackwalker stability issues Core Gecko Profiler nobody NEW --- 2021-05-12
1366133 Calling InternetGetConnectedStateExW() in ReadInternetOption() may cause hangs Core Networking xeonchen RESO FIXE 2020-02-27
1366241 Use of BinarySearch is slow in nsHtml5ElementName::elementNameByBuffer and nsHTML5AttributeName::nameByBuffer Core DOM: HTML Parser william RESO FIXE 2017-06-28
1366250 Flushing in nsFocusManager::CheckIfFocusable shows up significantly in Speedometer. Core DOM: Core & HTML bugs RESO FIXE 2019-03-13
1366263 RegExpMatcher, RegExpSearcher, and RegExpTester not always inlined in Speedometer Core JavaScript Engine: J arai.unmht RESO FIXE 2017-08-08
1366294 Refactor TelemetryHistogram internal storage Toolkit Telemetry chutten RESO FIXE 2017-07-25
1366353 Consider raising the priority of the compositor thread Core Graphics nobody RESO WONT 2019-01-22
1366356 Decrease the process priority of content processes that are not running a foreground tab Core DOM: Content Process amarchesini RESO FIXE 2020-03-03
1366358 [meta] Be better at relative scheduling of our thread priorities Core DOM: Core & HTML nobody NEW --- 2019-03-13
1366375 BaselineJIT: Add IC stub for array_push Core JavaScript Engine: J kvijayan RESO FIXE 2017-12-05
1366377 BaselineJIT: Add IC stub for String_split Core JavaScript Engine: J kvijayan RESO FIXE 2017-07-21
1366792 [Meta] Figure out why we are slow on Time to Hero Element on Gmail Core DOM: Core & HTML nobody RESO DUPL 2020-07-21
1366793 [Meta] Quantum Release Criteria: Figure out why we are slow on Time First Paint on YouTube Core DOM: Core & HTML nobody RESO DUPL 2019-03-13
1366802 [Meta] Quantum Release Criteria: Figure out why we are slow on Page Load on Talos Core DOM: Core & HTML nobody RESO INCO 2019-03-13
1366803 Many cleanup tasks can run before a setTimeout(0) handler that is called when a refresh driver tick is about to run Core DOM: Core & HTML nobody RESO FIXE 2019-03-13
1366874 [meta] WindowConstructor is expensive during startup Core Widget: Win32 nobody RESO FIXE 2017-08-01
1366877 [Meta] Quantum Release Criteria: Figure out why Browser chrome CC/GC pauses longer than 150 ms Core JavaScript: GC nobody RESO INCO 2019-03-05
1366881 [Meta] Quantum Release Criteria: Hasal Input Latency Core General nobody NEW --- 2019-02-21
1366960 [Input Latency] Firefox is 76% (172 ms) slower than Chrome in case Facebook - click to open chat tab Core General nobody RESO WORK 2017-08-17
1367004 [Input Latency] Firefox is 200% (27 ms) slower than Chrome in case Facebook - click to close chat tab Core General nobody RESO WORK 2018-11-29
1367029 Telemetry takes 93ms in isDefaultBrowser on startup on reference hardware Toolkit Telemetry alessio.placitelli RESO FIXE 2017-06-19
1367205 [meta] Very poor Polymer performance compared to Chrome (Web Components v0) Core DOM: Core & HTML nobody NEW --- 2021-04-21
1367206 Look into optimizing out the hashtable lookups from nsContainerFrame::DestroyFrom and nsContainerFrame::SafelyDestroyFrameListProp Core Layout mats RESO FIXE 2017-06-04
1367207 ImageLoader::DropRequestsForFrame is a bit hashtable-lookup happy Core Layout mats RESO FIXE 2017-07-04
1367209 nsCounterManager::DestroyNodesFor does an unconditional hashtable iteration on every frame destruction Core Layout mats RESO FIXE 2017-06-05
1367214 Frame destruction does unconditional hashtable lookups in the undisplayed map (in nsFrameManager::ClearAllMapsFor) Core Layout jwatt RESO FIXE 2017-08-15
1367217 ClearAllUndisplayedContentIn and ClearAllUndisplayedContentIn duplicate work Core Layout mats RESO FIXE 2017-06-08
1367219 DisplayItemData destructor does multiple hashtable lookups Core Layout mikokm RESO FIXE 2017-06-08
1367256 Notifications view on Facebook takes a lot of CPU Web Compatibility Desktop nobody RESO FIXE 2019-02-15
1367339 [Input Latency] Firefox is 60% (33ms) slower than Chrome in case Facebook - click to open emoji dialog in chat tab Core DOM: Core & HTML nobody RESO INCO 2019-03-13
1367352 [Input Latency] Firefox is 63% (35 ms) slower than Chrome in case Facebook - click right arrow on photo viewer Core Graphics nobody NEW --- 2018-01-16
1367416 WinTaskbar::Initialize() causes a library to be loaded on the main thread during startup Core Widget: Win32 agashlin RESO FIXE 2018-02-06
1367450 Captive portal detection shouldn't block first paint Firefox General nhnt11 VERI FIXE 2017-07-18
1367455 Scheduled GCs should avoid interrupting running GCs Core JavaScript: GC pbone RESO FIXE 2017-08-01
1367458 TabGroup::IsBackground() takes 300ms in the content process with telemetry enabled when running Core DOM: Core & HTML nika RESO FIXE 2019-03-13
1367551 Cancel HTTP2 push when the resource is already in the disk cache Core Networking: HTTP u408661 RESO FIXE 2017-11-06
1367665 [Input Latency] Firefox is 31% (53 ms) slower than Chrome in case GMail - Open Email Core JavaScript Engine nobody RESO INVA 2018-05-15
1367666 [Input Latency] Firefox is 100% (131 ms) slower than Chrome in case GMail - Reply Email Core JavaScript Engine mstange.moz RESO DUPL 2017-09-04
1367795 Incrementalise table sweeping Core JavaScript: GC jcoppeard RESO FIXE 2017-07-10
1367878 RegExp handling shows up in Facebook profile Core JavaScript Engine nobody NEW --- 2017-12-06
1367905 Try to run GC/CC slices, including forgetSkippable, during idle time Core XPCOM bugs RESO FIXE 2017-08-17
1367906 Avoid some overhead for backgrounds of elements without border-radius Core Web Painting bas RESO FIXE 2019-05-27
1368069 Drop the fast GC slice budget to 5ms in Nightly Core JavaScript: GC pbone RESO DUPL 2017-06-11
1368102 Move content script and extension page matching into C++ WebExtensions General kmaglione+bmo RESO FIXE 2018-08-22
1368208 Don't flush layout to determine whether scrollbox scroll buttons should be enabled/disabled Toolkit XUL Widgets dao+bmo RESO FIXE 2018-05-31
1368326 Reduce time spent in nsTArray destructors, when nsAutoMutationBatch goes out of scope Core DOM: Core & HTML dholbert RESO FIXE 2020-12-23
1368420 Map and Set and their iterators can't be nursery allocated Core JavaScript: GC jcoppeard RESO FIXE 2017-09-16
1368456 Remove uses of Promise.jsm from Firefox Toolkit Async Tooling florian RESO FIXE 2017-07-21
1368524 Add a telemetry probe for how long we spend processing NotifyObservers callbacks Core XPCOM nika RESO FIXE 2017-06-09
1368531 gfxPlatformFontList::InitOtherFamilyNames() seems to time out almost always Core Graphics: Text bignose1007+bugzilla RESO FIXE 2017-08-03
1368626 NativeSetProperty should have a fast-path when adding a new property to avoid unnecessary property lookups Core JavaScript Engine andrebargull RESO FIXE 2017-06-07
1368761 Investigate sweeping atoms table concurrently Core JavaScript: GC nobody NEW --- 2020-01-02
1368802 nsFrameIterator::GetPlaceholderFrame is doing a slow hashtable lookup (GetPlaceholderFrameFor) on all frames Core Layout mats RESO FIXE 2017-08-02
1368852 twitter's load "new results" feature takes a very long time compared to other browsers when you have a large number of tweets displayed (gecko profiler profile included) Core CSS Parsing and Comp emilio RESO FIXE 2017-09-13
1368972 Increase slice time for long-running incremental GCs Core JavaScript: GC bugs RESO FIXE 2017-09-07
1369042 Optimize the @@toStringTag and @@toPrimitive lookups Core JavaScript Engine jdemooij RESO FIXE 2017-09-11
1369140 Speedometer Inferno-DeletingItems test spends a lot of time under HTMLElementBinding::focus Core DOM: Core & HTML ehsan.akhgari RESO FIXE 2019-03-13
1369141 Hit testing in large tables has become extremely slow Core Layout mephisto41 RESO FIXE 2017-06-07
1369274 Dashlane extension slows down Firefox to a crawl on Reddit Firefox Extension Compatibil nobody RESO FIXE 2019-12-11
1369317 We suck at data URIs Core Networking valentin.gosu RESO FIXE 2017-12-24
1369508 Optimize calls to nsUXThemeData::InitTitlebarInfo() Core Widget: Win32 jwatt RESO FIXE 2017-06-21
1369694 [TSF] TSFTextStore shouldn't cache pref until first use Core Widget: Win32 masayuki RESO FIXE 2017-06-13
1369695 [TSF] TSFStaticSink shouldn't be initialized until first use Core Widget: Win32 masayuki RESO FIXE 2017-06-09
1369696 [TSF] ITfMessagePump and ITfKeystrokeMgr shouldn't be QIed from ThreadMgr until first use Core Widget: Win32 masayuki RESO FIXE 2017-06-15
1369697 [TSF] ITfDisplayAttributeMgr and ITfCategoryMgr should be created when they are required for composition string Core Widget: Win32 masayuki RESO FIXE 2017-06-09
1369734 Improve aborted-session ping scheduling for reduced performance impact Toolkit Telemetry alessio.placitelli RESO FIXE 2017-07-11
1369748 Buffering gray roots takes a long time Core JavaScript: GC jcoppeard RESO FIXE 2017-06-09
1369839 watching periscope.tv video on twitter is slow and janky Core Web Painting nobody RESO WORK 2017-12-07
1370027 Runaway subprocess_worker_unix.js worker thread is pegging an entire CPU Toolkit Async Tooling kmaglione+bmo RESO FIXE 2017-08-02
1370181 Don't start possibly-long-running GC work when there's not much time left in the budget Core JavaScript: GC nobody NEW --- 2021-04-27
1370377 Add markers for cycle collection Core XPCOM nobody RESO DUPL 2017-06-08
1370412 Excessive CPU usage by the content process at lumi.ava01.com Core Graphics aosmond RESO FIXE 2018-04-24
1370516 NSS should be initialized off main thread Core Security: PSM nobody NEW --- 2021-03-19
1370575 Overpainting when composing a reply in GMail Core Web Painting matt.woodrow RESO FIXE 2018-06-07
1370609 GetMinidumpType() can take a long time during startup Toolkit Crash Reporting ehsan.akhgari RESO FIXE 2017-06-09
1370644 Deadlock detector seems to pay no attention to the fact that a lock gets unlocked Core XPCOM ericrahm+bz RESO FIXE 2017-06-18
1370754 Setting innerHTML to editor is slower than Chrome Core Spelling checker ehsan.akhgari RESO FIXE 2017-06-18
1371061 nsBaseHashtable::GetOrInsert does two hashtable lookups in the Insert case Core XPCOM mats RESO FIXE 2017-06-08
1371095 ImageTracker does unnecessary hashtable lookups Core DOM: Core & HTML mats RESO FIXE 2019-03-13
1371157 cache results of system font lookups on Windows Core Widget: Win32 dbaron RESO FIXE 2017-06-12
1371523 Find bar uses sync IPC on each keypress Toolkit Find Toolbar gijskruitbosch+bugs RESO FIXE 2018-04-11
1371525 Try to avoid the RemoteLogins:findRecipes sync IPC Toolkit Password Manager me RESO FIXE 2017-09-03
1371646 Amazon access book result navigation profile Core Layout jfkthame NEW --- 2018-03-27
1371654 Gmail: Access Inbox profile Core JavaScript Engine sphink NEW --- 2018-02-22
1371659 Google Search profile Core JavaScript Engine nobody REOP --- 2018-01-24
1371661 Google image search profile Core JavaScript: GC nobody NEW --- 2018-01-24
1371668 Gmail: access YouTube link Core Graphics matt.woodrow RESO FIXE 2018-06-20
1371888 Cache plugin and plugin blocklist information so we can avoid loading the blocklist on startup in most cases Core Plug-ins gijskruitbosch+bugs VERI FIXE 2018-03-29
1371928 Add nsTHashtable::EnsureInserted/EnsureRemoved methods that indicates whether an existing entry was found Core XPCOM mats RESO FIXE 2017-06-18
1372599 nsAppShell::Init can wait quite a while calling CGSSetDebugOptions Core Widget: Cocoa jaas RESO FIXE 2017-07-18
1372602 The hidden window spends time creating a compositor / texture factory identifier that it will never use Core Graphics: Layers mchang RESO FIXE 2017-08-25
1372889 mozilla::net::nsHttpChannel::Connect() blocks the main thread on nsSiteSecurityService::HostHasHSTSEntry Core Security: PSM nobody RESO DUPL 2020-02-25
1373023 [meta] Laggy text input on Twitter direct messages (we flush layout too often, and reflow is slow) Core Layout nobody RESO FIXE 2018-11-10
1373079 nsNativeThemeWin::GetWidgetBorder and nsNativeThemeWin::GetMinimumWidgetSize are too slow Core Widget: Win32 dothayer RESO FIXE 2017-07-20
1373085 React Fiber triangle is broken due to performance Core DOM: Core & HTML afarre RESO FIXE 2019-03-13
1373095 nsTableCellFrame::GetRowSpan() is a tad slow Core Layout: Tables mats RESO FIXE 2017-06-17
1373394 [e10s] CSS transition of "margin-left" property is not smooth Core Graphics: Layers nobody NEW --- 2017-11-21
1373408 make nsIUpdateTimerManager support idle dispatch Toolkit General mconley RESO FIXE 2018-09-07
1373476 enabling lazy frame construction for non-element editable Core Layout m_kato RESO FIXE 2017-08-23
1373537 Videocontrols binding constructor triggers layout flushes Toolkit Video/Audio Controls ralin RESO FIXE 2020-01-25
1373660 Preallocated content process is launching before first paint Core DOM: Content Process gkrizsanits RESO FIXE 2018-09-05
1373672 FormDataListener.handleEvent() is extremely expensive when running speedometer Firefox Session Restore ttaubert RESO FIXE 2017-08-17
1373694 Don't block on beforeunload events from third-party tracking domain scripts Core DOM: Events nobody NEW --- 2017-10-13
1373708 Convert Jar channels to stop using main thread I/O Core Networking michal.novotny RESO FIXE 2018-03-25
1373723 Speedometer async benchmarks performance is very flaky Core DOM: Core & HTML nobody NEW --- 2020-04-18
1373773 PCompositorBridge::Msg_NotifyChildCreated sync IPC when opening tabs Core Graphics: Layers nobody NEW --- 2020-12-28
1373814 Track INPUT_EVENT_RESPONSE_COALESCED_MS during startup into a different probe Core Widget legnaleurc RESO FIXE 2017-08-31
1374011 substring shows up in Preact profiles Core JavaScript Engine nobody NEW --- 2017-10-06
1374338 Text selection in TreeHerder is very slow Core Layout agashlin RESO FIXE 2017-12-13
1374354 SessionRestore slows down page loading of a new tab Firefox Session Restore nobody NEW --- 2019-11-28
1374375 JS profiles do not get a pseudo stack in the beginning of a speedometer run Core JavaScript Engine nobody RESO DUPL 2017-10-10
1374382 Consider to process DOMLinkAdded event using animation frame callback + setTimeout(, 0) Firefox General nobody NEW --- 2018-10-29
1374665 Sending permissions for service workers during content process initialization can be very slow Core Permission Manager nika RESO FIXE 2018-03-28
1374797 Facebook is intermittently unusable on load due to GC Core JavaScript: GC jcoppeard RESO FIXE 2017-08-14
1374875 Replace the nsRange HTMLMediaElement::mSourcePointer with something faster Core Audio/Video: Playbac mats RESO FIXE 2017-07-13
1374934 Could js::NativeGetProperty be faster? Core JavaScript Engine nobody NEW --- 2019-10-04
1375022 Consider removing the Msg_GetClipboard sync IPC Core DOM: Copy & Paste an nobody NEW --- 2021-04-17
1375032 Composing on the chromium-review tool at normal speed is impossible due to style and layout flushes that trigger frame construction and reflow. Core CSS Parsing and Comp nobody RESO WORK 2019-02-01
1375075 HTMLMediaElement::LoadFromSourceChildren() flushes layout Core Audio/Video mats RESO FIXE 2017-06-23
1375218 Slow painting on israelnationalnews.com Core Graphics nobody NEW --- 2017-10-06
1375243 Remove sync PHandlerService::Msg_Exists IPC message Core DOM: Core & HTML mrbkap RESO FIXE 2019-03-13
1375244 Remove sync PContent::Msg_KeywordToURI IPC message Core DOM: Core & HTML standard8 RESO FIXE 2020-09-11
1375281 nsWindowMemoryReporter hurts performance badly Core DOM: Core & HTML cervantes.yu RESO FIXE 2019-03-13
1375287 TimeoutManager::SetTimeout should cache all preferences it needs Core DOM: Core & HTML ben RESO FIXE 2017-06-26
1375346 Facebook group page load Core JavaScript Engine nobody RESO DUPL 2020-07-21
1375565 GC: Do nursery allocation for external strings Core JavaScript: GC nobody NEW --- 2019-01-31
1375566 We can blow our slice budgets due to arena finalization taking too long Core JavaScript: GC sphink NEW --- 2018-07-13
1375568 Form AutoFill overhead in Speedometer Toolkit Form Manager nobody RESO FIXE 2017-09-19
1375631 Netflix browse triggers long IonBuilder compiles Core JavaScript Engine: J tcampbell RESO INVA 2020-10-23
1375997 Swagbucks is really slow at rendering. Web Compatibility Desktop nobody RESO WORK 2019-02-15
1376063 nsDisplayList::SortByZOrder() is slow Core Layout mats NEW --- 2019-12-27
1376287 consider using idle dispatch for firefox accounts sync Firefox Sync brennie RESO WONT 2019-03-18
1376511 Browser:Thumbnail:CheckState should be handled during idle period in child process Firefox New Tab Page ksteuber RESO FIXE 2017-08-10
1376525 APZ: Enable "apz.keyboard.enabled" by default Core Panning and Zooming rhunt VERI FIXE 2017-11-14
1376533 Use idleDispatch for Places expiration Toolkit Places agashlin RESO FIXE 2017-08-21
1376536 WhatsApp Web unuseable slow for longer conversations due to sync layout flush on input events Core Layout dholbert RESO FIXE 2021-02-26
1376557 finalisation slice can run late Core JavaScript: GC pbone ASSI --- 2021-03-21
1376651 mozilla::dom::CSPAllowsInlineScript shows malloc/free churn on Facebook Core DOM: Security kate+bugzilla RESO FIXE 2017-08-08
1376698 speedometer v2 VueJS async subtests take about twice as long in Firefox vs. Chrome (mostly running JS) Core JavaScript Engine nobody NEW --- 2019-07-23
1376799 Optimize Object.prototype.toString more Core JavaScript Engine jdemooij RESO FIXE 2017-08-02
1376861 Tune nursery parameters for the speedometer benchmark Core JavaScript: GC nobody NEW --- 2019-07-23
1376891 Investigate eagerly collecting the nursery in an idle callback Core JavaScript: GC f103119 RESO FIXE 2017-11-05
1376948 Make "string" + array faster Core JavaScript Engine nobody NEW --- 2020-04-12
1377131 Try to trigger collector slices at times which disturb page js less (at least with iframes loaded after the top level page has been loaded) Core DOM: HTML Parser bugs RESO FIXE 2019-02-24
1377253 Reflow is slow on twitter direct messages (and other sites), with lots of reflow time spent in nested flex reflow Core Layout dholbert RESO WORK 2018-12-11
1377257 gfxFont::GetRoundOffsetsToPixels adds malloc/free churn Core Graphics: Text jfkthame RESO FIXE 2017-10-09
1377316 mozilla::DisplayItemData::AssertDisplayItemData is slow Core Web Painting nobody NEW --- 2018-01-09
1377329 nsFrameList::GetLength() calls in nsDisplayListBuilder::MarkFramesForDisplayList() are slow Core Web Painting u459114 RESO FIXE 2017-07-17
1377339 obj_toString() called from isDate() in Angular could be faster Core JavaScript Engine nobody NEW --- 2020-04-12
1377377 Blocking on reading in string bundle to report error message to console slows down Facebook group page load Core DOM: Core & HTML ksteuber RESO FIXE 2019-03-13
1377710 Compiling lots of unused branches can be expensive Core JavaScript Engine nobody NEW --- 2020-01-04
1378192 Loading re:Dash dashboards janks other content processes Core Graphics: Layers nobody NEW --- 2017-10-06
1378717 Investigate optimising gray root buffering Core JavaScript: GC jcoppeard RESO FIXE 2017-07-12
1378930 make SchedulerGroup dispatch smarter when dealing with nsINamed runnables Core XPCOM bevistseng RESO FIXE 2017-07-27
1379263 PoisonIOInterposterMac.cpp should not fstat in IsValidWrite if the write is for an IPC message Core XPCOM nobody RESO INVA 2017-08-15
1379275 Selectboxes/dropdowns in servicenow are laggy/difficult to use when dom.forms.select.customstyling is enabled Core Layout: Form Control nobody NEW --- 2019-11-03
1379286 Use a kernel driver for profiling on Windows Core Gecko Profiler nobody NEW --- 2019-12-17
1379611 Use Bookmarks.jsm in editBookmarkOverlay.js Firefox Bookmarks & History mak RESO FIXE 2017-07-18
1380061 Could NodeListBinding::DOMProxyHandler::get() be optimized? Core DOM: Core & HTML nobody NEW --- 2021-04-29
1380773 Consider adding large tenured promotion counts to MinorGC marker Core JavaScript: GC nobody NEW --- 2019-01-31
1380778 Speedometer triggers minorGC very often Core JavaScript: GC jcoppeard RESO FIXE 2017-07-18
1380967 Telemetry doesn't distinguish minor GC at start of major GC and between slices Core JavaScript: GC jcoppeard RESO FIXE 2017-07-17
1380972 Reduce our definition for what constitutes a long GC slice Core JavaScript: GC jcoppeard RESO FIXE 2017-07-19
1380974 BufferList default size for IPC messages maybe too large Core IPC hchang.mozilla RESO FIXE 2017-07-26
1381071 Consider caching getComputedStyle styles in display: none subtrees. Core CSS Parsing and Comp emilio NEW --- 2020-12-15
1381382 facebook_ail_click_open_chat_tab Core General nobody RESO WORK 2017-08-17
1381383 facebook_ail_click_photo_viewer_right_arrow is too slow Core CSS Parsing and Comp sstangl NEW --- 2018-10-01
1381384 Performance analysis on gmail_ail_compose_new_mail_via_keyboard Core General nobody NEW --- 2018-10-01
1381387 Performance analysis on gmail_ail_reply_mail Core JavaScript Engine nobody REOP --- 2018-10-01
1381857 Long (multi-second) pauses in Mac GL code waiting on mutexes when loading bankofamerica.com Core Graphics nobody NEW --- 2017-10-06
1381961 Enabled shared global for JSMs pref Core XPConnect continuation RESO FIXE 2017-09-19
1381976 Pre-compile JSM scripts into the shared JSM global rather than compilation scope Core XPConnect kmaglione+bmo RESO FIXE 2017-10-01
1382311 obama wikipedia page has slow restyles 5-10 times during pageload Core CSS Parsing and Comp nobody RESO FIXE 2017-09-13
1382319 ABP causes us to spend 5x more time in selector matching on obama wikipedia page Core CSS Parsing and Comp nobody NEW --- 2018-01-23
1382427 Support running reftest in a mode than runs the test with Retained Display lists on, and references with it off Core Web Painting jwatt RESO FIXE 2017-11-15
1382837 Optimize array_join Core JavaScript Engine kvijayan RESO FIXE 2020-04-15
1382899 Reduce Promise overhead in the DownloadLegacy.js progress events Firefox Downloads Panel paolo.mozmail RESO FIXE 2018-01-26
1382968 console calls shouldn't be piped to the parent until it is any useful DevTools Console poirot.alex RESO FIXE 2018-06-13
1383205 [e10s] long drop down menu results in constant beach ball Core Layout: Form Control felipc RESO FIXE 2017-10-04
1383210 Try to precompute the bucket range Toolkit Telemetry dothayer RESO FIXE 2017-09-06
1383215 Cu.import is far too slow for the cached module case Core XPConnect kmaglione+bmo RESO FIXE 2017-08-19
1383242 Hang [@ nsRange::ExcludeNonSelectableNodes] when doing text selection in this testcase Core DOM: Core & HTML jimnchen+bmo VERI FIXE 2017-10-07
1383299 Consider initiating a speculative connection in order to prepare Necko to give the parser in the content process data faster upon navigations from the url bar Firefox Address Bar jj.evelyn RESO FIXE 2020-01-24
1383364 for..of significantly slower in certain testcases Core JavaScript Engine: J nobody NEW --- 2021-02-06
1383367 Add JS helper to determine if a layout flush is required Core DOM: Core & HTML kmaglione+bmo RESO FIXE 2019-03-13
1383444 3.01ms uninterruptible reflow at nextStep@chrome://global/content/bindings/progressmeter.xml:83:19 Toolkit XUL Widgets nobody NEW --- 2018-03-20
1383538 lightningmaps.org very slow, makes the content process unresponsive Core JavaScript Engine nobody UNCO --- 2017-10-06
1384008 Consider lowering heap thresholds Core JavaScript: GC nobody NEW --- 2017-10-06
1384049 Malloc bytes threshold triggers a non-incremental GC Core JavaScript: GC jcoppeard RESO FIXE 2017-10-18
1384101 v55b11 seems slow again. (Adminer 4.3.1) Firefox Untriaged nobody RESO WORK 2017-08-01
1384178 assemblePing can be slow, mostly due to cloneInto Toolkit Telemetry nobody RESO WORK 2018-01-05
1384562 Optimize the obj_toString call in OrdinaryToPrimitive Core JavaScript Engine nobody NEW --- 2020-04-12
1384669 Avoid refcount churn in BidiParagraphData::ResetData Core Layout: Text and Fon dholbert RESO FIXE 2017-08-18
1384714 Use subscript loader to load browser.xul scripts Firefox General kmaglione+bmo RESO FIXE 2017-08-30
1384727 Make QueryInterface use integer IDs Core XPCOM nobody NEW --- 2018-10-06
1384808 Improve performance for linear searches in the shape lineage Core JavaScript Engine dpalmeiro RESO FIXE 2019-02-19
1384900 Array.prototype.sort is slow on very sparse arrays Core JavaScript: Standard nobody NEW --- 2019-11-07
1384970 djvu-html5 demo spends lots of time in cross compartment wrapper overhead Core JavaScript Engine nobody NEW --- 2017-10-10
1385396 Calling setExperimentActive forces graphics initialization Toolkit Telemetry dothayer RESO FIXE 2017-08-07
1385437 DisplayList building time on GMail is quite high Core Layout bas RESO INVA 2018-05-15
1385463 Enable APZ autoscrolling by default Core Panning and Zooming botond VERI FIXE 2017-11-03
1385466 Performance regression compared with stable on http://ncase.me/trust/ Firefox Untriaged nobody RESO INCO 2017-08-07
1385861 Fine tune nsDisplaySVGText::Paint Core Web Painting u459114 RESO FIXE 2017-08-02
1385865 Revert MAR generation to old format for 56.0b1 Release Engineering Release Requests nobody RESO WONT 2017-08-14
1386001 Array.prototype.push often not inlined in Speedometer Core JavaScript Engine: J nobody RESO DUPL 2017-12-07
1386015 [e10s] <option> elements with inherited colors generates very inefficient styling in the parent Core Layout: Form Control zbraniecki RESO FIXE 2017-10-26
1386104 400ms onload jank in this React testcase (Chrome: 120ms) Core JavaScript Engine nobody NEW --- 2017-12-07
1387319 Getting WebGL context can apparently take forever Core Canvas: WebGL cleu NEW --- 2017-09-18
1388034 Avoid extra string copies in RegExpGlobalReplaceOpt by returning the input string when no match was found Core JavaScript: Standard nobody NEW --- 2017-10-06
1388134 mozilla::OSFileConstantsService::InitOSFileConstants does startup main thread IO Toolkit OS.File dothayer RESO FIXE 2018-10-17
1388179 Excessive time spent in layout/style when clicking rightarrow on Facebook photo viewer Core CSS Parsing and Comp nobody NEW --- 2021-04-17
1388221 Cache existing module exports when defining lazy module getters Core XPConnect kmaglione+bmo RESO FIXE 2018-03-14
1388263 Suspend the taskbar refresh in WindowsJumpLists.jsm when computer becomes idle Firefox General nobody NEW --- 2017-11-21
1388538 Add ICs for slotful own-prop Xray property access (property on the expando) Core JavaScript Engine nobody NEW --- 2018-10-29
1388848 Consider tuning the smooth scroll speed for mouse wheel scrolling Firefox General kats RESO DUPL 2020-08-18
1389443 nsHandlerService-json.js does main thread IO during startup to load its json file Firefox File Handling dothayer RESO FIXE 2019-07-02
1389712 switching to a Google Slides tab is slow (long repaint) Core Graphics bas ASSI --- 2018-01-04
1389840 Cache more computed manifest data in the startup cache WebExtensions General kmaglione+bmo RESO FIXE 2018-06-19
1389847 Don't add caller location to sandbox name if an explicit name is provided Core XPConnect kmaglione+bmo RESO FIXE 2017-08-15
1389848 isServiceInstantiatedByContractID should return false rather than throw when component isn't instantiated Core XPCOM kmaglione+bmo RESO FIXE 2017-08-16
1389868 Create bootstrap Sandboxes without indexedDB constructor by default Toolkit Add-ons Manager kmaglione+bmo RESO FIXE 2017-08-15
1390084 No gecko profile for Talos test with "mozharness: --geckoProfile" syntax Testing Talos rwood RESO FIXE 2017-08-31
1390232 Wrapping typed array in object has performance impact Core JavaScript Engine nobody UNCO --- 2017-12-07
1390274 Lots of URI parsing in network predictor Core Networking u408661 RESO FIXE 2017-08-25
1390382 Make nsCaret::NotifySelectionChanged() less expensive Core Layout ehsan.akhgari RESO FIXE 2017-08-22
1390928 sendStyleSheetInfo() shows up in profiles during page show Firefox Menus nobody NEW --- 2021-04-22
1391110 Convert FrameLoader bindings to WebIDL Core DOM: Core & HTML kmaglione+bmo RESO FIXE 2019-03-13
1391298 More sessionstore overhead when running speedometer Firefox Session Restore nobody NEW --- 2019-07-23
1391405 Speed up schema normalization WebExtensions General kmaglione+bmo RESO FIXE 2018-06-19
1391576 Stop doing main-thread I/O in FileUtils.getFile for the most common case Toolkit General paolo.mozmail RESO FIXE 2017-08-21
1391707 Use idle dispatch in JSONFile/DeferredSave/DeferredTask Toolkit Async Tooling kmaglione+bmo RESO FIXE 2019-10-21
1391710 Nightly still has 2.2 times poorer JS perfomance than Chrome on Mozilla Log Analyzer Core JavaScript Engine nobody NEW --- 2019-05-28
1391792 [meta] Reduce extension and plugin blocklist entries to improve Firefox startup time Toolkit Blocklist Implementa jorge RESO FIXE 2019-01-02
1392011 Convert WebNavigation/DocShell to WebIDL Core DOM: Core & HTML nobody RESO WONT 2020-09-01
1392460 deltaMode default should be DOM_DELTA_PIXEL Core DOM: Events emilio RESO FIXE 2021-04-30
1392679 [meta] iPhone 5C app startup can be 20sec Firefox for iOS General nobody RESO INVA 2019-01-17
1392876 Enable coalescing mouse events to be once per refresh cycle (enable the pref) Core DOM: Events stone123456 RESO FIXE 2020-02-26
1392888 Form AutoFill uses the super inefficient getElementsByTagName() API Toolkit Form Manager lukechang1209 RESO FIXE 2017-09-05
1392928 Consider to keep unused Ion LifoAllocs because freeing it is not cheap Core JavaScript Engine nicolas.b.pierron NEW --- 2018-12-27
1393098 Investigate if nsTextFrame::CharacterDataChanged could return early if the frame is already dirty Core Layout dholbert RESO FIXE 2017-09-07
1393120 hotmail/outlook.com's mouse-over sluggish Core Layout nobody RESO WORK 2019-02-12
1393621 ext-contextualIdentities.js is loaded at startup when it isn't needed WebExtensions General kmaglione+bmo RESO FIXE 2018-06-19
1393685 GetThemeMargins() can be extremely expensive Core Widget: Win32 agashlin RESO FIXE 2017-09-08
1393712 for-await-of with Async Generator is slow Core JavaScript Engine nobody NEW --- 2021-04-24
1393909 Remove sync messaging in WebRequestContent WebExtensions Request Handling mixedpuppy RESO FIXE 2018-06-19
1393977 Compiling the same script again and again for each embedded YouTube video Core JavaScript Engine nobody NEW --- 2018-11-01
1394735 Enabling privacy.resistFingerprinting causes jank in jquery scrolling Core Layout nobody UNCO --- 2020-04-08
1394761 Hasal input latency case facebook_ail_scroll_home_1_txt regressed median from 22ms to 44ms on 7/29 Core JavaScript Engine sstangl NEW --- 2017-10-06
1394778 rel=preload for no-cache resources Core DOM: Networking michal.novotny RESO WONT 2019-11-28
1395012 MediaStreamGraph doesn't shut down when the last user is gone Core Audio/Video: MediaSt nobody RESO INVA 2018-01-04
1395066 Breaking tab data collection into chunks Firefox Session Restore nobody NEW --- 2020-04-12
1395274 Scripted modification of the selection can jank the browser Core DOM: Selection nobody NEW --- 2018-03-25
1395644 Performance issues on web.whatsapp.com Firefox Untriaged nobody RESO DUPL 2018-01-03
1395813 Investigate whether we can remove the browser-element-api:call JS sync IPC Core DOM: Core & HTML nobody NEW --- 2019-05-22
1395814 Investigate whether we can remove the Addons:Event:Run JS sync IPC Firefox Extension Compatibil nobody RESO FIXE 2019-06-19
1395815 Consider removing web progress shims Core DOM: Content Process nobody RESO DUPL 2018-03-31
1396479 multi-second jank/spinner when switching to certain tabs Core Graphics nobody RESO WORK 2017-09-22
1396613 Simplify per-class tenuring actions by using the object moved hook Core JavaScript: GC jcoppeard RESO FIXE 2017-09-19
1396822 Remove dead branches from IonBuilder. Core JavaScript Engine: J nobody RESO INCO 2021-01-13
1396870 imgLoader::CheckCacheLimits() janks vnc_playback.html Core ImageLib ben RESO FIXE 2017-09-07
1396980 [FIX] Spending too much time making ranges for spellchecker on Facebook page Core Spelling checker jj.evelyn RESO FIXE 2018-06-25
1397092 High Cpu/GPU usage due to "Ping Pong" loading indicators in Firefox 57 affecting browser performance Firefox Theme nobody RESO DUPL 2018-02-07
1397297 nsCycleCollector::FreeSnowWhite() could be more incremental Core XPCOM bugs RESO FIXE 2018-09-07
1397360 Fix BrowserUtils.promiseLayoutFlushed to always return a Promise and unregister its callbacks to avoid memory leaks Core DOM: Core & HTML nobody RESO WONT 2019-03-13
1397448 Lots of HTTP connections result in poor performance caused by MessageChannel.jsm WebExtensions Request Handling kmaglione+bmo RESO FIXE 2018-06-19
1397450 Eliminate or at least lessen main thread IO in UpdateService.jsm Toolkit Application Update nobody NEW --- 2020-11-06
1397549 Tune the nursery size to keep nursery collections under 5ms Core JavaScript: GC pbone ASSI --- 2019-03-26
1397627 IPCBlobInputStream must be always async and non-blocking Core DOM: File amarchesini RESO FIXE 2017-09-15
1397706 Preload off main thread more dll files Toolkit Startup and Profile nobody RESO INAC 2021-05-17
1398119 NoteDirtyElement is either called too often or is too slow or both Core DOM: Core & HTML bholley RESO FIXE 2019-03-13
1398600 [meta] Bug 1397092 + other issues with Firefox57 causing Severe page loading delays in Firefox 57 32-bit builds compared to Firefox 57 builds from 2017-08-20 Core DOM: Content Process nobody NEW --- 2018-07-30
1398669 Hasal case test_firefox_gmail_ail_compose_new_mail_via_keyboard is 100 ms (50%) slower with heavy user profile Core General nobody RESO INCO 2017-12-05
1398928 Fix the argument to SpeciesConstructor Core JavaScript: Standard andrebargull RESO FIXE 2017-09-20
1399962 Consider reducing the number of content processes for dual core CPUs Core DOM: Content Process nobody RESO WONT 2019-02-02
1400278 Attribute malloc memory usage to the Zone rather than the Runtime Core JavaScript: GC jcoppeard RESO FIXE 2017-10-02
1400787 Using software video decoders (include VP9) ramps up computer fans on Macbook. Core Audio/Video: Playbac nobody NEW --- 2020-07-31
1401345 Loading HR4909 (Defense Authorization Act) takes a very long time and causes content process to hang Core XSLT nobody NEW --- 2017-11-21
1401508 Avoid constructing the GetCapabilitiesExecutor function for default Promises in Promise.all/race Core JavaScript: Standard andrebargull RESO FIXE 2017-10-04
1401624 Use object-biased NaN boxing instead of double-biased on x86-64 Core JavaScript Engine iireland RESO FIXE 2019-08-06
1402910 drag gecko hashtables into the current century Core XPCOM froydnj+bz NEW --- 2020-06-22
1402958 Extremely slow page startup due to js::str_normalize Core JavaScript Engine bhackett1024 RESO FIXE 2017-10-11
1403823 High CPU on twitch TV stream Core Audio/Video: Playbac nobody NEW --- 2021-04-19
1404140 Consider flushing layout in a more fine-grained way in getComputedStyle. Core CSS Parsing and Comp emilio RESO FIXE 2019-10-23
1404723 Firefox takes up unexpected amounts of CPU on "Marking bugs for the Firefox 57 release" page Core Graphics aosmond RESO DUPL 2020-05-23
1404909 Improve performance of paste/drag and dropping many bookmarks Firefox Bookmarks & History standard8 RESO FIXE 2018-07-06
1404950 new Promise(resolve => {}) is a performance footgun Core JavaScript Engine nobody NEW --- 2021-05-01
1405281 Keystrokes trigger full-page (and slow) paint with contenteditable cells with borders or border-collapse Core Layout: Tables nobody NEW --- 2020-05-09
1405606 Freeze on Cloudflare analytics page Core General nobody RESO WORK 2018-01-07
1406622 stylo: use invalidation framework to handle restyles needed in response to content insertion/removal Core CSS Parsing and Comp emilio NEW --- 2020-03-10
1407143 Consider not collecting the nursery for each marking GCSlice Core JavaScript: GC pbone RESO FIXE 2018-11-30
1408039 Spread ...args are 99% slower than arguments Core JavaScript Engine nobody RESO WORK 2019-05-03
1409114 Figure out a better way to create display items for column backgrounds Core Layout: Tables matt.woodrow RESO FIXE 2019-07-22
1410464 Janky window resize on testcase similar to the webconsole UI with lots of flex children Core Layout nobody RESO INVA 2020-06-12
1413567 Enable Retained Display Lists for Android Core Web Painting tnikkel RESO FIXE 2019-06-27
1413763 Hidden arrow panels keep trying to composite at 60fps Core Graphics: Layers nobody NEW --- 2021-02-18
1413796 High CPU use on sbnation.com article page Core Graphics nobody NEW --- 2018-12-13
1413810 Performance is poor on Ebay.ca Watch List Core Layout nobody UNCO --- 2018-02-05
1414284 Marmalead search page causes lots of slow graphics computation Core Graphics nobody NEW --- 2018-01-24
1414938 Spike in memory use when navigating away from a page that uses a lot of memory Core XPCOM nobody NEW --- 2018-10-28
1416541 Consider switching to incremental GC in the last phases of a GC. Core JavaScript: GC pbone RESO WONT 2018-07-13
1417122 Noticeable lag when scrolling, typing or changing tabs on scaled Retina display Core Graphics nobody UNCO --- 2017-11-21
1417221 Prevent background thumbnails from causing high CPU usage Toolkit General nobody NEW --- 2019-01-23
1417699 Stop using a property bag for filter attributes Core Web Painting dothayer RESO FIXE 2020-05-06
1417768 Opening new windows very slow Core Graphics nobody RESO WORK 2021-02-07
1417970 Make recascading when only custom properties change cheaper Core CSS Parsing and Comp emilio NEW --- 2020-07-30
1418013 Investigate slow page load performance on Wikipedia Core Networking nobody RESO INCO 2018-07-10
1418161 stylo: Huge perf hit on painting and MotionMark benchmarks w/ Stylo and uBlock Origin Core CSS Parsing and Comp bholley RESO FIXE 2018-02-06
1418816 Table with a fixed top-left background image causes severe slowdown Core Graphics: Layers jnicol REOP --- 2019-01-15
1418822 Scrolling with impulse mousewheel feels too slow, specially compared with Chrome/Edge Core Widget: Win32 kats RESO FIXE 2020-10-15
1418886 LoginManagerContent.jsm leaks DOM nodes via loginFormRootElements Toolkit Password Manager mconley RESO FIXE 2018-01-05
1419053 [meta] Firefox's disk write behaviour is worse than other browsers' in some situations Firefox General nobody NEW --- 2021-03-15
1419519 Firefox Quantum lags when editing files on GitHub. Core Layout: Text and Fon nobody RESO DUPL 2018-04-02
1420369 stylo: 6.21 - 6.54% remote-tsvg / remote-twitter (android-6-0-armv8-api16, android-7-1-armv8-api16) regression on push db56323cd08f4883e4824199b441a3141be655e5 (Thu Nov 23 2017) Core CSS Parsing and Comp m_kato NEW --- 2019-11-25
1420440 Optimize the Function constructor Core JavaScript Engine nobody NEW --- 2019-06-26
1422090 [meta] high GPU load and excessive power usage Core Graphics tnikkel RESO FIXE 2020-07-12
1423324 Add support for promoting parts of the WebRender scene to native layers Core Graphics: WebRender nobody NEW --- 2020-07-12
1423896 Make the All Bookmarks folder for the left pane a virtual query Toolkit Places standard8 RESO FIXE 2018-06-12
1424057 Excessive time spent running JS (in "transitionHandler" function), when clicking rightarrow on Facebook photo viewer Core JavaScript Engine: J nobody NEW --- 2021-04-17
1424740 console.log of an object graph in a worker is very slow Core DOM: Core & HTML nobody NEW --- 2019-03-13
1425040 Firefox is very slow entering/leaving Twitter “lightbox” effects when the DOM is large Core CSS Parsing and Comp nobody NEW --- 2020-12-25
1425058 stylo: Profile StyleBench. Core CSS Parsing and Comp hikezoe.birchill RESO FIXE 2018-03-14
1425106 Jupyter Lab very slow in Firefox, with rapid long flex reflows (triggered from JS .offsetTop calls) Core Layout: Flexbox nobody NEW --- 2020-04-27
1425144 0.34 severe hangs / khr in CreateFileW while creating jump lists Firefox General dothayer RESO FIXE 2019-02-20
1425389 Low javascript performance on Firefox Quantum Core Graphics nobody UNCO --- 2019-07-24
1426447 Avoid refresh driver ticks in windows that aren't ready for first paint yet Core Layout nobody NEW --- 2021-02-20
1427033 Throttle animations in 0-opacity element subtree Core DOM: Animation emilio RESO FIXE 2020-05-07
1427417 Mouse hover on https://kangax.github.io/compat-table/esnext/ is atrociously slow Core Graphics nobody NEW --- 2019-01-16
1427607 severe jank when deleting sites from the history sidebar Toolkit Places nobody NEW --- 2018-10-29
1427739 Map/Reduce slow compared in Firefox Nightly vs Chrome Core JavaScript Engine nobody NEW --- 2021-01-05
1428972 RexBench is slower than Chrome/WebKit Core JavaScript Engine nobody NEW --- 2018-10-30
1429522 Improve compositing power usage on macOS by using CoreAnimation Core Widget: Cocoa mstange.moz RESO FIXE 2020-07-21
1430884 Throttle transform animations on out of view element that the transform animation does not have 0% or 100% keyframe value Core DOM: Animation hikezoe.birchill RESO FIXE 2018-06-27
1432019 Improve scrolling on Android by dispatching vsync notifications on the UI thread Firefox for Android General kats RESO FIXE 2020-12-21
1433007 Allow the nursery to use less than a single chunk Core JavaScript: GC pbone RESO FIXE 2019-06-26
1434978 css blur is slow on EventBrite Core Graphics nobody NEW --- 2020-03-04
1435141 Main thread IO in the parent process in nsNSSComponent::HasUserCertsInstalled Core Networking valentin.gosu RESO FIXE 2019-03-25
1437914 Typing 25-30 chars on an input with expensive regexp pattern causes browser to hang Core DOM: Editor nobody NEW --- 2019-06-16
1437988 Consider adding onProgressChanged method for smoother loading appearance GeckoView General esawin RESO FIXE 2018-12-27
1438768 Writing an email in outlook.com's web-interface is slow Core Layout nobody RESO WORK 2019-02-19
1438986 Firefox nightly hangs when focusing input fields on simpletax.ca Toolkit Form Autofill nobody RESO WORK 2020-05-01
1438989 Long-running NotifyIconObservers::Run on main-thread in parent process when closing a tab Toolkit Places nobody NEW --- 2018-10-29
1439412 Linux: Evaluate only using fontconfig in the parent process Core Graphics: Text nobody NEW --- 2020-06-07
1439511 The tab loading throbber has high CPU usage on macOS Firefox Theme nobody RESO WORK 2019-08-16
1439519 Use eager-push/lazy-pull to get active plugin information for TelemetryEnvironment Toolkit Telemetry gijskruitbosch+bugs RESO FIXE 2018-04-02
1441918 Antimalware Service Executable (Windows Defender) very active / high CPU when using Firefox External Software Af Other nobody NEW --- 2021-01-02
1443066 Try to understand why we're slower than Chrome on StyleBench "Positional pseudo classes : Adding leaf elements: Async" (& similar "Removing" measurement) Core CSS Parsing and Comp nobody NEW --- 2020-04-25
1443299 Serious jank on reddit (generally) Core JavaScript: GC nobody RESO DUPL 2018-06-05
1444013 The collector should yield after nursery collection if the budget is exceeded Core JavaScript: GC pbone ASSI --- 2018-11-15
1446027 2.00ms uninterruptible reflow at attach@resource:///modules/ExtensionPopups.jsm:488:5 WebExtensions Frontend lgreco RESO FIXE 2019-04-29
1446072 Rightmove is very slow to load on both Firefox Desktop Core JavaScript Engine nobody RESO WORK 2021-03-10
1446161 Make ContentParent::PreallocateProcess asynchronous Core DOM: Content Process jld RESO FIXE 2020-03-17
1446904 nsBaseDragService::InvokeDragSession function - freeze when using touch input Core Widget: Win32 jhofmann VERI FIXE 2018-04-26
1448039 Use ICState consistently for all ICs Core JavaScript Engine: J khyperia RESO FIXE 2018-10-11
1448096 During inspector panel drag-to-resize operation, JS triggers two reflows per event loop (1 extra) DevTools Inspector gijskruitbosch+bugs RESO FIXE 2018-08-08
1448130 Overpainting (full-area paint flashing) in browser UI (toolbars, devtools, sidebars) when resizing window Core Web Painting nobody NEW --- 2018-10-29
1448672 [css-flexbox] https://ci.chromium.org/p/chromium/g/main/console?limit=500 takes very long to load and hangs the content process on Sync reflow Core Layout nobody VERI FIXE 2018-04-21
1448844 Firefox hangs/freezes randomly when loading web pages on Debian Core DOM: Core & HTML nobody RESO DUPL 2019-03-13
1448944 Avoid ContentPrefService roundtrip when loading initial about:blank Firefox Tabbed Browser dothayer RESO FIXE 2018-04-28
1449027 Website scrolling incorrectly on Firefox (checkerboarding due to slow paints) Core Graphics: Layers bas NEW --- 2018-10-29
1450059 Have a singleton thread for low-priority work Core XPCOM jaas RESO FIXE 2019-12-10
1450130 [meta] Reduce the pain from ghost windows Core General nobody NEW --- 2020-10-03
1451093 clearRect appears to be much slower now Core Canvas: 2D nobody NEW --- 2019-11-07
1451517 Really high CPU and memory usage on zerohedge.com due to ads Core JavaScript Engine nobody NEW --- 2019-02-05
1451985 Ghost windows from dropbox shared image link page Core DOM: Core & HTML continuation RESO FIXE 2019-03-13
1452214 https://jrmuizel.github.io/perf-tests/moving-balls.html spends a long time > 110ms in style Core CSS Parsing and Comp emilio RESO FIXE 2020-04-29
1452829 Canvas is not optimized for clipping to rectangles Core Graphics dwlsalmeida NEW --- 2018-10-29
1453142 Testcase where we're not optimizing DOM things in top-level script with global scope assignment. Core JavaScript Engine nobody NEW --- 2018-10-29
1453351 [Form Autofill] Parsing Roll20 character sheet for phone numbers leads to janks Toolkit Form Autofill nobody NEW --- 2018-10-29
1454345 GeneratorObjects still save NewTarget value even though its value is always NullValue Core JavaScript Engine nobody RESO DUPL 2018-05-18
1454414 slow rasterizing on http://themaninblue.com/experiment/eclipse/ Core Graphics nobody NEW --- 2019-01-17
1454477 [meta] Investigate progress bar behavior difference between GeckoView and WebView GeckoView General esawin NEW --- 2020-12-20
1454529 tune nglayout.initialpaint.delay setting GeckoView General bugs RESO DUPL 2021-03-15
1454586 Optimize resume point creation in IonBuilder Core JavaScript Engine: J nobody NEW --- 2019-06-21
1454822 Cache intrinsic sizes of flex containers Core Layout dholbert RESO FIXE 2021-05-06
1455118 Scrolling is a bit janky in card mode at reddit (post-redesign), with long waits mid-refresh-driver-tick between "reflow" & "display list" Core Web Painting nobody NEW --- 2018-10-29
1456035 Add native QueryInterface helper with fast path for XPCWrappedJS Core XPConnect kmaglione+bmo RESO FIXE 2018-05-29
1456040 CPU usage spikes, delays on 2017 13-inch MacBook Pro when rendering Core Graphics nobody UNCO --- 2019-03-07
1456137 JIT code seems to spend a lot of time checking to see whether objects have getters or setters Core JavaScript Engine: J nobody NEW --- 2018-05-03
1456241 dropbox shared image link page is very slow to close Firefox Tabbed Browser nobody NEW --- 2018-12-11
1456581 Gmail Sent folder locks up browser for minutes Core Layout: Text and Fon nobody NEW --- 2018-10-29
1456626 nsJARChannel::asyncOpen can still block Core Networking: JAR emalysz ASSI --- 2020-05-21
1456638 Checkerboarding while scrollbar-dragging due to slow display list build on specific page with table layout Core Web Painting nobody NEW --- 2019-05-29
1456843 HTML loading hangs for minutes while updating DOM Toolkit Form Manager mconley RESO FIXE 2019-01-08
1456964 It takes a long time to re-layout the plaintext page when the sidebar is opening or closing until move the mouse in the content area (with long time spent in RFindLineContaining) Core Layout: Block and In nobody NEW --- 2019-07-17
1457321 Move bundled dictionaries into omni.ja Core Spelling checker kmaglione+bmo RESO FIXE 2019-10-18
1457413 Scroll jank due to slow paint on gsmarena.com animation Core Graphics dothayer RESO FIXE 2018-11-05
1458076 Nimbledroid's buzzfeed.com page load test is 2x slower in GeckoView than WebView GeckoView General nobody RESO WORK 2019-03-27
1458079 Nimbledroid's wikia.com page load test is 2x slower in GeckoView than WebView GeckoView General nobody RESO WORK 2019-03-27
1458894 Window title in the taskbar changes multiple times when restoring session Firefox Session Restore nobody NEW --- 2018-10-29
1459875 The new Reddit layout is very slow to load even with browser.tabs.20FpsThrobber TRUE Core Graphics nobody NEW --- 2018-09-29
1460123 long e10s tab spinner on twitter after opening view source Core Layout: Text and Fon nobody RESO DUPL 2019-08-16
1460264 Slow CSS animation in the header of paypal.com Core Graphics nobody NEW --- 2018-10-29
1461100 the new gmail refresh page feels to load slower compared to chrome Web Compatibility Desktop sefeng RESO DUPL 2019-02-15
1461666 Randomly scrolling gets quite janky Core Panning and Zooming nobody RESO WORK 2019-02-19
1462373 1.39ms uninterruptible reflow at _calculateMaxHeight@resource:///modules/PanelMultiView.jsm:1032:9 Firefox Menus nobody NEW --- 2018-10-29
1462374 1.05ms uninterruptible reflow at _adjustFocusAfterTabSwitch@chrome://browser/content/tabbrowser.js:1200:5 Firefox Tabbed Browser gijskruitbosch+bugs RESO INCO 2018-09-18
1462377 3.86ms uninterruptible reflow at PT__rebuild/<@chrome://browser/content/places/browserPlacesViews.js:1062:13 Firefox Bookmarks & History nobody RESO FIXE 2018-05-29
1462843 Firefox is twice as slow as Google Chrome running es-membrane tests Core JavaScript Engine nobody NEW --- 2020-10-18
1463462 Incrementalize gray marking Core JavaScript: GC jcoppeard RESO FIXE 2019-06-20
1465205 Nested grid/flex layout is slow in mobile UI at http://www.wikia.com/fandom Core Layout nobody NEW --- 2019-03-25
1465986 Permission Manager initialized the DB on profile startup Core Permission Manager dothayer RESO DUPL 2019-01-15
1466529 Stylo is malloc heavy when parsing property values for style.foo = "bar"; Core CSS Parsing and Comp u480271 RESO FIXE 2018-07-27
1466704 trying to View Source on twitter.com stalls out entire content process (spending lots of time in nsBidiPresUtils::TraverseFrames->nsBidiPresUtils::ResolveParagraph->SplitInlineAncestors) Core Layout: Text and Fon nobody NEW --- 2020-05-09
1466729 The Login overlay is stuttering when scrolling the background page Firefox for Android General nobody RESO WORK 2020-12-21
1466922 Styling jank (134ms style flush) when loading new Reddit layout Core CSS Parsing and Comp nobody NEW --- 2018-10-29
1467124 Fix WindowProxy optimizations in the JIT for same-compartment realms Core JavaScript Engine jdemooij RESO FIXE 2019-03-31
1467305 Google Inbox open/close on a category is much slower compared to Chrome Core Graphics: Layers nobody NEW --- 2018-10-12
1467697 Loading page is x2 slower than chrome Core JavaScript: GC pbone NEW --- 2021-05-01
1468246 High variability in performance testing with large images Core Layout nobody NEW --- 2021-04-21
1468455 [Meta] Firefox execution time is 12-20 times that of chrome， test case SVG/TextOnPathSimple.html Core SVG nobody NEW --- 2021-03-24
1468476 F5 causes content re-validation and this is slow Core DOM: Navigation nobody NEW --- 2021-04-26
1469383 Duplicate stub attachment for GetProp in browser tests Core JavaScript Engine: J nobody NEW --- 2018-10-29
1469403 We dump display lists from about:newtab a bunch when it's not even visible Core Web Painting kats RESO FIXE 2019-07-15
1469947 Infinite painting on https://material.io/design/ (background image has animated SVG, but covered up by other stuff) Core Web Painting nobody NEW --- 2018-10-29
1470299 In Nexus 4 API 23, m.yelp.de progress stuck at 25% GeckoView General esawin RESO FIXE 2018-12-27
1470324 Don't load EnterprisePoliciesContent until a policy is checked Firefox Enterprise Policies felipc RESO FIXE 2018-07-27
1470365 Use shared memory for string bundles loaded in content processes Core Internationalization kmaglione+bmo RESO FIXE 2018-07-13
1470369 Don't collect the nursery for every sweeping GCSlice Core JavaScript: GC jcoppeard RESO FIXE 2020-07-21
1470447 JPEG decoder should post an invalidation for each row Core ImageLib aosmond RESO FIXE 2018-07-17
1471025 Use shared memory for preferences in content processes Core Preferences: Backend kmaglione+bmo RESO FIXE 2021-01-25
1471029 High cpu/gpu usage and hangs on page-http://telegra.ph/Telegram-X-03-26 & other pages Core Audio/Video: Playbac nobody NEW --- 2019-11-07
1471099 The text and images scroll jerkily when scrolling on Firefox Android. Core Layout nobody RESO WORK 2018-07-05
1471110 slideshow doesn't work Core JavaScript Engine nobody NEW --- 2020-02-11
1472491 Add tooling to lazily load content actors from JSMs based on events/messages/page loads Toolkit Async Tooling kmaglione+bmo RESO FIXE 2019-01-22
1472512 Expanding large number of hidden/nested comments on youtube hangs the page for a few seconds Core JavaScript Engine sstangl RESO WORK 2018-09-17
1472546 Moving position:absolute elements performance far worse (i.e. terrible) with vertical-rl pages than vertical-lr pages Core Layout emilio RESO FIXE 2019-10-25
1472941 Slow loads and performance at dvhn.nl, compared to Chrome Core Layout nobody NEW --- 2020-05-07
1473110 slow reflows when typing in to a long compose-message body at Google Inbox Core Layout nobody RESO WONT 2020-05-09
1473156 Don't block process launch waiting for the child to send a Mach port Core IPC jld RESO WONT 2018-10-18
1474384 <xul:browser>.currentURI for lazy browsers is very eager to allocate nsIURI objects Firefox Tabbed Browser ehsan.akhgari RESO FIXE 2018-07-13
1474813 Long synchronous reflows in CSS2Properties.paddingRight, at vespaclubsanquiricodorcia.cloud (probably related to "slick" carousel library) Core Layout nobody RESO DUPL 2019-09-24
1474985 css blur is slow on this cnn.com slideshow Core Graphics nobody RESO DUPL 2019-01-22
1475020 Slow reflows at cnn.com slideshow, with lots of time spent in nested grid reflow Core Layout nobody NEW --- 2019-09-11
1475222 minutes-long pageload for page with large list of files, with most time spent in frame construction & RFindLineContaining in particular Core Layout sefeng RESO WORK 2019-07-31
1475952 TelemetrySession.jsm:gatherMemory is janky Toolkit Telemetry nobody RESO DUPL 2018-11-07
1476101 Optimize Windows sandbox policy construction Core Security: Process Sa emalysz NEW --- 2020-03-09
1476201 Open a compare svn branches view in jetbrains upsource janks Core JavaScript Engine nobody UNCO --- 2018-10-25
1476241 GMail UI is slow, check mails or scrolling usually happens after a delay in seconds Core Graphics nobody UNCO --- 2019-12-02
1476398 Performance issues on HP site Core DOM: CSS Object Mode nobody NEW --- 2019-01-14
1476748 Reduce duplication and unify responsibility for window sizing Firefox General nobody NEW --- 2018-11-01
1476857 2048game.com has worse performance in Firefox as compared to Chrome browser Firefox General nobody NEW --- 2018-10-29
1477211 'undefined' as the default array destructuring default value leads to bad type info Core JavaScript Engine: J nobody RESO WORK 2021-01-05
1478078 Appreciable amount of time spent in blob image creation on Google slides Core Graphics: WebRender jmuizelaar RESO FIXE 2019-01-23
1478104 Slow typing (1-5s delay) for GDocs with many active contributors Core JavaScript Engine: J kvijayan NEW --- 2020-04-18
1478148 maybe softoken can stop accessing cert9.db-journal and cert9.db-wal all the time for read-only operations (affects reading Thunderbird mail) NSS Libraries nobody NEW --- 2019-08-18
1478637 TrackingProtection.cancelAnimation (from browser-trackingprotection.js) does sync style flushes Firefox Site Identity jhofmann RESO FIXE 2018-11-24
1478953 style.foo = bar changes are slow Core CSS Parsing and Comp nobody NEW --- 2021-04-17
1479083 URL bar seems to trigger multiple layouts when browser window is resized at certain sizes Firefox Toolbars and Customi nobody NEW --- 2018-10-29
1480477 Removing DOM children where positional pseudo-classes are involved is really slow. Core CSS Parsing and Comp nobody NEW --- 2020-07-14
1481124 Menu takes longer to open in Firefox than in chrome Core JavaScript Engine nobody NEW --- 2020-02-07
1481310 Slow painting in React DevTools slows down interactions Core Web Painting matt.woodrow RESO WONT 2019-04-29
1481519 Enable tab warming by default on macOS Firefox Tabbed Browser mconley RESO FIXE 2019-02-21
1481783 React updates can trigger lots of GC activity Core JavaScript: GC nobody NEW --- 2020-10-09
1481967 100% cpu usage and high memory use on page with multiple embedded videos Core Audio/Video: Playbac nobody NEW --- 2018-10-29
1482240 ThreadResponsiveness uses nsITimer in a way which may disturb idleness checks Core Gecko Profiler nobody NEW --- 2020-04-16
1482264 Lots of paints during tab switch Core DOM: Content Process nobody NEW --- 2019-03-19
1483280 Preference to lazy load images and frames natively (LazyLoad) Core Layout nobody RESO FIXE 2020-05-22
1483345 Try and re-attach NewObject stubs after GC Core JavaScript Engine: J nobody NEW --- 2019-12-29
1483963 Multi-second browser jank after transition between normal and full-screen video Core DOM: Animation bugs RESO FIXE 2020-04-12
1485092 uniqlo.com page load is 2x slower in GeckoView than WebView Core Layout nobody RESO WORK 2019-01-29
1486362 CPU usage is extremely high at githubuniverse.com Core Layout nobody NEW --- 2019-06-27
1486980 Browser occasionally gets stuck in a state where it is processing thousands of events (kinto-offline-client using IndexedDB) External Software Af Other mathieu RESO FIXE 2018-10-26
1487287 Move process launch off the I/O thread and into a thread pool Core IPC jld RESO FIXE 2020-01-11
1487465 LastPass causes 6s hang in content WebExtensions Developer Outreach nobody VERI FIXE 2019-04-15
1487906 [meta] Network panel recording overhead DevTools Netmonitor nobody NEW --- 2019-11-26
1488435 Significant key input delay when typing on large Google Docs Core JavaScript Engine nobody NEW --- 2021-05-21
1488759 BinaryArith ICs missing in gdocs Core JavaScript Engine: J mgaudet RESO FIXE 2018-09-10
1488768 SetElem hits IC fallback for out-of-order dense elements Core JavaScript Engine: J kvijayan RESO DUPL 2018-10-11
1488775 Add JIT support for string + number Core JavaScript Engine: J mgaudet RESO FIXE 2018-09-17
1488780 decommit can be slow while holding the allocator lock Core Memory Allocator nobody NEW --- 2019-08-27
1488786 [gdocs] Missing JIT IC for GetElem on sparse elements Core JavaScript Engine: J mgaudet RESO FIXE 2018-10-05
1488860 High CPU usage Firefox Untriaged nobody RESO INCO 2018-10-10
1488863 Consider to fire timers less often during page load Core DOM: Core & HTML nobody RESO DUPL 2019-03-13
1488871 AsyncScrollPortEvent as an WillPaintObserver causes extra layout flushes during page load Core Layout emilio RESO FIXE 2019-06-02
1489036 Make StringBuilder::ToString look for characters to escape in each text node and attribute value only once Core DOM: Core & HTML nobody NEW --- 2019-03-13
1489142 FlagAllOperandsAsHavingRemovedUses can take a very long time Core JavaScript Engine: J nicolas.b.pierron RESO FIXE 2019-04-08
1489253 Delete/open emails in Gmail is slower than Chrome Core JavaScript Engine: J nobody NEW --- 2019-02-07
1489572 LifoAlloc: double chunk size on each allocation Core JavaScript Engine nicolas.b.pierron RESO FIXE 2019-01-15
1490510 400ms browser jank after transition between normal and full-screen video Core DOM: Animation nobody NEW --- 2019-10-24
1490792 140ms of FontFace::DoLoad when loading Google Doc Core Layout: Text and Fon cam RESO FIXE 2019-07-21
1490798 Long Ion compiles during Google Docs loading Core JavaScript Engine nobody RESO INVA 2021-04-27
1490847 [meta] Long-standing Ion Compilation Time Issues Core JavaScript Engine: J nobody NEW --- 2020-10-26
1490849 Off-Main-Thread Baseline Compilation Core JavaScript Engine: J nobody NEW --- 2018-11-28
1490890 nsFlexContainerFrame::MarkIntrinsicISizesDirty is too aggressive Core Layout: Flexbox dholbert RESO FIXE 2019-07-12
1490917 Gmail tab hangs when trying to forward and edit a long Ticketmaster email Core JavaScript Engine nobody NEW --- 2018-11-07
1491111 Slow restyles when loading cnn.com in network panel Core CSS Parsing and Comp nobody NEW --- 2018-10-29
1491902 Enable background process manager on Windows on Nightly Core DOM: Content Process nobody RESO DUPL 2018-09-17
1492218 [meta] Report First Input Delay telemetry for page loads Core Performance nobody NEW --- 2021-04-21
1492538 Don't reflow flex items if they're not dirty and their size from the flex algorithm hasn't changed Core Layout dholbert RESO FIXE 2021-03-25
1492611 Regexes are very slow typing in web.whatsapp.com with many images. Core JavaScript Engine nobody NEW --- 2018-10-29
1492963 Stop doing storage initialization at startup WebExtensions General kmaglione+bmo RESO FIXE 2018-11-16
1493218 GitHub PDF render is about 6x slower in Firefox compared to Chrome or Edge Core Graphics nobody NEW --- 2021-05-17
1493225 GeckoSession.goBack() can be unresponsive during a heavy page load. GeckoView General jporterbugs RESO FIXE 2020-10-06
1493420 10 seconds spent in Stylo on page Core CSS Parsing and Comp emilio RESO FIXE 2019-10-17
1493603 External loads needlessly force creating an about:blank content viewer with confusing (wrong?) unload semantics Core DOM: Navigation nobody NEW --- 2018-10-29
1493643 window.open creates an initial about:blank window twice Core General nobody NEW --- 2018-10-31
1493751 Handle case when compositor receives layers but MozLayerTreeReady will not be serviced by the parent in time Core Graphics: Layers nobody NEW --- 2018-11-13
1493767 Firefox freezes when trying to restore many tabs after a crash Firefox Session Restore nobody RESO WORK 2019-02-28
1494363 High CPU usage on OSX with Google Docs Core JavaScript Engine nobody NEW --- 2019-05-16
1494485 portainer.io - visible lag between blur in and out effect Core Graphics nobody NEW --- 2018-12-13
1494504 IonSetPropertyIC stubs transition to Generic too quickly on GDocs Core JavaScript Engine: J nobody RESO DUPL 2018-10-23
1494537 Add IC support for adding and updating elements past the end of a sparse array Core JavaScript Engine: J kvijayan RESO FIXE 2019-01-11
1494623 www.google.com - Doodle stutters while playing when using Direct2D canvas Core Canvas: 2D nobody NEW --- 2018-12-08
1495213 Entering live view on Facebook is janky Core Graphics: Layers nobody NEW --- 2018-12-13
1495734 Long pauses on reloading a page that was using large amounts of memory Core JavaScript: GC nobody RESO INVA 2021-04-27
1496096 Horrible performance on runningworld due to media decoding Core Audio/Video: Playbac rjesup ASSI --- 2021-04-27
1496473 YouTube desktop_polymer.js is not run fast enough in Firefox Web Compatibility Desktop nobody RESO WORK 2021-01-22
1496514 Long stalls (10-15 seconds) while paging down on load of very large Google doc Core JavaScript Engine nobody NEW --- 2020-04-18
1496554 MediaDecoder threads can contend on the allocator lock too much Core Audio/Video: Playbac nobody NEW --- 2020-04-18
1496847 GETELEM Generic Cache attaches for dense elements, shadowing more specific optimization opportunity. Core JavaScript Engine: J kvijayan RESO FIXE 2018-10-23
1497626 Investigate if back/forward/reload from UI could interrupt JS Core DOM: Navigation nobody NEW --- 2018-10-29
1498459 Twitter spends a lot of time building display lists. Core Web Painting nobody NEW --- 2020-12-25
1498484 Sketchfab frame rate is too slow in FxR on Oculus Go Core JavaScript: GC nobody NEW --- 2020-09-01
1498485 hubs.mozilla.com frame rate with an empty scene is too slow in FxR on Oculus Go Core JavaScript Engine nobody NEW --- 2020-06-09
1499170 Panorama appliance is exceedingly slow in Firefox (selector-matching in quirks-mode document) Core CSS Parsing and Comp emilio RESO FIXE 2018-11-17
1499324 [meta] Consider compiling the interpreter dynamically Core JavaScript Engine: J jdemooij RESO FIXE 2020-12-15
1499465 Considering stopping collection of crash reports when KillHard'ing from the shutdown timer Core DOM: Content Process mconley RESO FIXE 2018-11-21
1499883 1.41ms uninterruptible reflow at onxbldragend@chrome://browser/content/tabbrowser.xml:1825:15 Firefox Tabbed Browser felipc RESO FIXE 2018-10-24
1500154 Significant amount of time spent in PLT stubs for geckoview on Android GeckoView General mbrubeck RESO FIXE 2018-12-27
1501305 Facebook Group: Firefox took 2 times user timing than Chrome Core JavaScript Engine: J nobody RESO INCO 2021-04-27
1501328 JSVM/CacheIR - Add optimized stub for out-of-bounds GETELEMs of indexed properties on Arrays Core JavaScript Engine: J kvijayan RESO FIXE 2018-10-25
1501415 5+ second delay before first paint, when loading 27mb plaintext log file Core Layout: Text and Fon nobody NEW --- 2018-10-24
1501424 Investigate local hardware PGO impact on page load tests Firefox Untriaged acreskey RESO WORK 2018-10-25
1502146 kinto shouldn't do heavy weight operations in the main thread of the parent process Cloud Services Firefox: Common mathieu RESO FIXE 2018-11-23
1502473 [meta] JSVM - Top level investigation of page-load behaviour on top sites. Core JavaScript Engine nobody RESO FIXE 2019-05-27
1502529 Coalesce touchmove Core DOM: UI Events & Foc bugs RESO FIXE 2020-04-28
1503119 A lot of time spent in query_selector Core DOM: CSS Object Mode nobody NEW --- 2021-04-22
1503259 Animated page load throbber causes a permanent ~9% CPU load for Renderer threads of the main process Core Graphics: WebRender nobody REOP --- 2021-02-23
1503371 Large local files with many pictures load extremely slow Core Performance nobody NEW --- 2019-07-16
1503425 User reports lag such as when opening several new tabs Core Graphics nobody UNCO --- 2018-11-07
1503704 Very high CPU usage on fast.com Core Networking nobody NEW --- 2020-04-09
1503830 Firefox significantly impacted by high CPU load compared to other browsers / programs Core Performance nobody UNCO --- 2019-11-17
1503919 Long restyle time during page load on raptor-tp6-amazon-firefox Core CSS Parsing and Comp nobody NEW --- 2021-04-21
1503942 Canvas handling shows up while loading Facebook (in raptor) Core Canvas: 2D nobody RESO INVA 2021-04-21
1503961 100ms of bytecode encoding during pageload on eventbrite.ca Core JavaScript Engine froydnj+bz RESO FIXE 2019-06-21
1503973 MemoryTelemetry.jsm janks the browser Core XPCOM kmaglione+bmo RESO FIXE 2018-12-12
1504065 Run background-color animations on the compositor for non-WebRender Core Layout hikezoe.birchill RESO FIXE 2020-04-05
1504121 carlsen.porschedealer.com - Site is nearly unresponsive Core CSS Parsing and Comp nobody RESO WORK 2019-02-21
1504337 Consider if it makes sense to use HTTP1.1 on cellular connections Core Performance nobody NEW --- 2019-11-22
1504886 Twitch.tv video playback is laggy and freezes using GV 67 on Fire TV Core JavaScript: GC nobody VERI FIXE 2019-04-27
1505192 twitch.tv site loads slow compared to Chrome Core JavaScript Engine nobody NEW --- 2021-05-01
1505254 FrameNeedsReflow() shouldn't invalidate ancestors' ISizes up further than an abspos ancestor Core Layout: Positioned dholbert RESO FIXE 2019-02-22
1505258 Loading mobile Instagram site takes 2x longer using GeckoView Core JavaScript Engine jporterbugs RESO WORK 2021-04-27
1505290 41.73% tsvgx (linux64-qr) regression on push 7a308f25794fefdd541d3c913fb807c6ee495615 (Tue Nov 6 2018) Core Graphics: WebRender nobody RESO WORK 2020-02-17
1505483 Getting a list of audio devices on about:support is super slow sometimes Core Audio/Video nobody NEW --- 2019-06-01
1505513 Fennec & GeckoView - slow cold start time Firefox for Android General nobody RESO INCO 2020-12-21
1505533 graphics data gathering (and/or canvas webgl context initialization) from about:support is slow Core Graphics nobody NEW --- 2018-11-16
1506331 High CPU utilization when rapidly hovering over tabs Firefox Tabbed Browser nobody NEW --- 2020-06-11
1506376 Consider to make PCompositorBridge::DidComposite high priority message Core Layout bugs RESO FIXE 2020-02-19
1506765 Do an optimization to not flush animations which are running on the compositor in various places where we call FlushPendingNotification Core DOM: Animation nobody NEW --- 2018-11-13
1507271 tripadvisor.ca loads very slowly in GeckoView Example GeckoView General nobody RESO WORK 2021-04-22
1507432 IonBuilder: Prevent inlining when the caller block is cold. Core JavaScript Engine: J nobody RESO FIXE 2021-01-05
1507508 Adding markers to a Google map is visibly slower than in IE, Chrome, etc. Core Performance rjesup RESO INVA 2021-01-04
1508327 Clearing mark bitmaps can take a long time Core JavaScript: GC nobody RESO DUPL 2021-03-04
1509228 Optimizing nsGlobalWindowOuter::NotifyContentBlockingState() seems to have an impact on pageload Core DOM: Core & HTML nobody NEW --- 2020-07-15
1509376 Very long reflow (332ms) on pageload of Amazon.com (OSX) Core Layout: Text and Fon nobody RESO DUPL 2019-09-19
1510226 NS_NewNamedThread blocks the main thread Core XPCOM dothayer RESO FIXE 2021-03-15
1510262 nsIncrementalDownload causes a lot of jank with main thread I/O while downloading updates in the background Core Networking: HTTP nobody NEW --- 2020-11-06
1510275 Accessing the local storage causing too much work Firefox Protections UI ehsan.akhgari RESO FIXE 2018-12-10
1511381 Synchronous layout flush coming from PluginChild.jsm during page load Core Plug-ins timdream RESO FIXE 2019-02-08
1511731 Slow loading, janky scrolling and delayed / pixelated painting on dailymail.co.uk Firefox for Android General nobody RESO INCO 2020-12-21
1512768 Pottermore hamburger menu slide-in animation is janky Core Layout nobody NEW --- 2020-02-24
1514011 Investigate script execution order and also possibly yield if there is pending vsync. Core DOM: Core & HTML bas NEW --- 2021-04-21
1514113 Move ReprotectRegion and mprotect off the main thread Core JavaScript Engine: J nobody NEW --- 2020-09-01
1514413 Opening http://datakitchen.tumblr.com completely hangs system, causes high disk I/O Core Networking honzab.moz RESO WONT 2019-05-08
1515414 Defer GCs in background tabs/processes during pageload Core JavaScript: GC nobody NEW --- 2021-04-27
1515473 CPU intensive slideshow on http://thesantaclausparade.com/ Core Graphics nobody NEW --- 2019-01-24
1515780 Consider more aggressively throttling deviceorientation events Core DOM: Device Interfac nobody NEW --- 2019-11-25
1516552 ETP Strict delays the visibility of all site content because of blocked GA/GTM resources Core Privacy: Anti-Tracki mstange.moz RESO FIXE 2021-02-04
1516780 Loading rust iterator docs feels much slower than in Chrome Core CSS Parsing and Comp emilio RESO FIXE 2019-04-10
1517135 BytecodeEmitter::finishTakingSrcNotes is quadratic, and can take multiple seconds on large JavaScript files. Core JavaScript Engine iireland RESO FIXE 2019-02-14
1517254 Slow load and long delay before search field can be interacted with on https://scouts.org.uk Core CSS Parsing and Comp nobody NEW --- 2019-02-11
1517509 Coalesce wheel events at the refresh driver level instead of at the IPC boundary Core DOM: UI Events & Foc nobody NEW --- 2021-04-23
1517534 Poor performance of simple "vector" operations on arrays Core JavaScript Engine: J nobody NEW --- 2019-01-16
1517635 Opening and closing the Hotels.com date picker is super janky in Fennec GeckoView General nobody RESO WORK 2019-09-23
1517758 10.09 - 17.22% tp5o responsiveness / tp5o_webext responsiveness (linux64, windows7-32) regression on push 1b13a38c51e5640aa716d8d367c44e101c3835e3 (Thu Jan 3 2019) Core DOM: Core & HTML nobody RESO WONT 2020-09-17
1517916 Skeletal Animation: Slow (FPS) on Firefox compare to Chrome Core JavaScript Engine: J nobody NEW --- 2019-02-14
1518344 Investigate using async for PBackground::EnsureRDDProcessAndCreateBridge Core Audio/Video: Playbac jya-moz RESO FIXE 2020-11-19
1518677 Avoid collection during page load Core JavaScript: GC nobody REOP --- 2019-11-24
1518857 provide optimized implementations of float modulus Core JavaScript Engine: J nobody NEW --- 2021-02-26
1518995 Outstream.com page tilt effect is very laggy and jumpy with WebRender enabled Core Graphics: WebRender nobody NEW --- 2020-12-11
1519497 Firefox slows down and freezes when Linkedin fetches new jobs to view (churning in flexbox layout) Core Layout: Flexbox nobody RESO WORK 2020-08-19
1519513 Can spend a really long time hanging the main thread in the parent process running gfxMacFontFamily::FindStyleVariations Core Layout: Text and Fon nobody NEW --- 2019-01-28
1519567 Ensure imglib notifies layout in a timely manner that an image can be painted Core ImageLib bugs RESO FIXE 2019-03-04
1520251 Slow performance for accessing objects in an array with 7+ elements Core JavaScript Engine: J nobody UNCO --- 2019-02-26
1520366 LifoAlloc can allocate crazy amounts of memory loading a Facebook page (temporarily) Core JavaScript Engine: J nicolas.b.pierron VERI FIXE 2020-06-03
1520505 Banner ad taking much longer to retrieve/render in Firefox than in Chrome Core Performance nobody RESO INVA 2019-07-29
1520729 jetbrains "upsource" file-view hangs the browser, when scrolled Core Layout nobody NEW --- 2019-01-26
1520894 Low-latency video playback via MediaSource causes extremely high CPU/GPU usage and poor playback performance. Core Audio/Video: Playbac nobody NEW --- 2021-01-21
1520932 Spurious Choreographer vsync messages when running tests GeckoView General nobody NEW --- 2019-11-24
1521729 Make nsHttpChannel::AsyncOpen wait (async) for HSTS data to be available before connecting to non-https URLs Core Networking: HTTP kershaw RESO FIXE 2020-02-25
1522150 Add a DeferredTimers queue that executes before the normal Idle queue Core XPCOM rjesup RESO FIXE 2019-02-11
1522196 InitOtherFamilyNamesRunnable can slow down first page load and take > 100ms Core Layout: Text and Fon nobody NEW --- 2020-06-17
1522263 me.me - loading the site is slow in Desktop and freezes Fennec Core Web Painting nobody NEW --- 2019-01-24
1522282 Delayed image loading on low end ARM devices Core Performance sefeng ASSI --- 2021-04-28
1522288 Should we start image load using microtask and not Gecko's current stable state (== end-of-task)? Core Layout: Images, Vide sefeng RESO FIXE 2019-07-26
1522311 On Android, scrolling m.imgur.com displays blank frames for long periods of time and shows images with a delay Core Performance nobody NEW --- 2020-04-18
1522316 Network loads seem to be started very late in this profile Core DOM: Service Workers bugs RESO FIXE 2019-04-18
1522612 9gag gets progressively slower to render as user scrolls down page (infinite scroll) Core Performance nobody UNCO --- 2019-12-02
1522838 High input latency on Google Docs Core Performance nobody RESO DUPL 2019-07-16
1523028 [meta] Performance of "about:config" Toolkit Preferences nobody NEW --- 2020-10-29
1523922 LoginManagerContent.jsm shows up in the page load profiles, consider rewriting in C++? Toolkit Password Manager nobody RESO INCO 2020-09-09
1524056 Performance: Atrocious processing performance on news.google.com! Core Layout nobody RESO FIXE 2021-05-04
1524104 Consider lowering priority for offscreen iFrame processes Core DOM: Content Process nobody NEW --- 2021-03-19
1524334 Zooming in on Google Docs takes a long time Core JavaScript Engine nobody NEW --- 2019-04-17
1524384 Twitch.tv video's (vod) freeze during playback on MacOS Core Audio/Video: Playbac nobody NEW --- 2019-03-05
1524615 Performance on heavy ReactJS site is a lot slower than Chromium Core JavaScript Engine nobody RESO WORK 2021-04-27
1524880 https://takelessons.com/blog/best-guitar-songs-of-all-time-z01 is very slow to load on mobile Core JavaScript Engine nobody NEW --- 2019-03-07
1525229 https://www.tiny.cloud/docs/demo/full-featured/ renders very slow Core Performance nobody RESO DUPL 2019-10-10
1525260 RSA Encrypt is VERY SLOW in firefox Core JavaScript Engine: J nobody UNCO --- 2019-03-21
1525320 Add config prefs that let us tell media and animated images to paint only the first frame Core Performance whawkins RESO FIXE 2020-02-17
1525478 Certain CSS animations cause extreme framerate drops (because hardware-acceleration was blocked for nvidia driver 24.21.13.9731 on GeForce GTX 760) Core Performance nobody RESO WONT 2019-02-13
1525983 Non-optimal GC behavior on skeletal animation testcase Core JavaScript: GC pbone RESO FIXE 2019-06-11
1526315 Non-integer typed array access can lead to repeated bailouts Core JavaScript Engine: J whawkins RESO FIXE 2019-03-13
1526487 [ARM64] Sometimes very laggy tab switching Core Graphics nobody NEW --- 2019-02-21
1527037 Scroll jank when mousewheel-scrolling slide thumbnails on Google Docs (with lots of time spent painting & in GetFrameForPoint) Core Web Painting nobody NEW --- 2019-02-19
1527712 nsFileChannel (called e.g. by fetch) shouldn't do main thread I/O for local files Core Networking: File honzab.moz RESO FIXE 2019-12-09
1527786 Incredibly bad intermittent typing lag on the new Twitter theme Core JavaScript Engine nobody NEW --- 2019-11-15
1527828 Remove insecure password field detection code for the address bar Toolkit Password Manager mozilla+bmo RESO FIXE 2019-10-28
1527879 localeCompare is very slow due to a lot of main thread I/O Core JavaScript: Internat andrebargull RESO FIXE 2019-07-08
1528285 [meta] Allow call of AsyncOpen and OnStart/OnStopRequest off the main thread Core Networking: HTTP nobody NEW --- 2021-04-08
1529044 Saving intermediate certs to the DB has a significant detrimental effect on page load time (android) Core Security: PSM dkeeler RESO FIXE 2019-04-11
1529110 Some sites' page loads are slower when Tracking Protection is enabled GeckoView General nobody RESO INVA 2019-04-19
1529276 resource:///modules/WindowsJumpLists.jsm still does main thread I/O Firefox Shell Integration nobody NEW --- 2020-11-06
1529283 nsAnonTempFileRemover::RemoveAnonTempFileFiles does main thread I/O off a timer Core XPCOM nobody NEW --- 2020-11-06
1529333 Re-evaluate which resources we auto-download on GeckoView first run and when GeckoView General nobody RESO WORK 2021-04-29
1529343 JavaScript algebra calculation on FireFox is slower than on Chrome Core JavaScript Engine: J nobody NEW --- 2020-02-18
1529551 omni.ja files are read using main thread I/O for every content process Core Networking: JAR mh+mozilla RESO FIXE 2019-03-15
1530071 High CPU load on https://www.megamarsch.de/dresden due to invisible load spinner with opacity: 0 Core CSS Transitions and emilio RESO FIXE 2020-07-13
1530212 Loading https://doc.servo.org/smallvec/trait.Array.html spends multiple seconds in parsing and GC during page load Core JavaScript Engine nobody RESO WORK 2021-04-27
1531024 High CPU Usage when switching tabs Core Performance nobody RESO INCO 2019-03-01
1531123 Upload speed is very slow in comparison to the expected. Works fine with both Chrome and Explorer. Core Networking nobody NEW --- 2020-04-05
1531354 Investigate if we can skip HashStore::Open during startup Toolkit Safe Browsing dlee RESO FIXE 2020-06-26
1531373 Panomoments is slow too load Core DOM: Networking nobody RESO INVA 2019-03-18
1531455 Limit the number of chrome Custom Elements that get loaded for GeckoView GeckoView General bdahl RESO FIXE 2020-02-28
1531917 Gather telemetry on effectiveness of the bfcache Core Performance sefeng RESO FIXE 2019-05-15
1532115 [arm64-windows] Idle battery consumption on imgur is almost 2x higher than Edge Core Performance nobody NEW --- 2019-10-10
1532444 Dynamic change to marker style causes it to continuously repaint forever Core SVG longsonr RESO FIXE 2019-03-28
1532651 4.43% about_preferences_basic (osx-10-10) regression on push 623c6ca6ed6cf8128cebf9944524f3be13e0d4d2 (Fri Mar 1 2019) Core XUL nobody RESO WONT 2020-09-18
1532720 Speakerdeck expensive paints for switching slides Core Graphics nobody NEW --- 2019-03-06
1532749 [Direct3D 11 (Advanced Layers)] Loading a website causes an insane spike in RAM (15GB) even with a clean profile, when it works fine on other browsers Core Graphics: Layers nobody NEW --- 2019-05-15
1532838 Tune minimum nursery size using a more realistic benchmark Core JavaScript: GC pbone RESO FIXE 2019-05-08
1533328 js::InitDateTimeState loads tzres.dll on the main thread during early startup Core JavaScript Engine andrebargull RESO FIXE 2019-08-20
1534431 Nightly hangs in local storage when following links on file:/// Core Storage: localStorag jvarga RESO FIXE 2019-06-19
1534712 FetchBodyConsumer<Derived>::BeginConsumeBodyMainThread shouldn't make nsLocalFile do main thread I/O Core DOM: Networking amarchesini RESO FIXE 2019-06-07
1535134 nsLayoutUtils::DisplayRootHasRetainedDisplayListBuilder is slow Core Web Painting nobody NEW --- 2019-03-20
1535381 Experiment with setting thread affinity in worker threads Core Performance nobody NEW --- 2019-08-16
1536171 Determine optimal android http memory and disk cache values Core Performance nobody RESO FIXE 2019-06-04
1536497 SandboxBrokerClient::DoCall takes lots of time when loading http://www.espn.com/ Core Canvas: WebGL nobody RESO WORK 2021-04-26
1536622 [10.14.4] Poor battery life on MacBook Pro Core Graphics nobody NEW --- 2019-06-27
1536739 Performance is slow/janky with a full complement of add-ons, restored session, opening discarded tabs WebExtensions General nobody NEW --- 2019-08-19
1537587 We can spend lots of time resolving fonts for wikipedia.org on FireTV/GeckView Core Graphics: Text jfkthame RESO FIXE 2019-03-28
1537652 Investigate more selective compacting GC. Core JavaScript: GC nobody NEW --- 2019-06-24
1537661 Slow response in Gmail Core JavaScript Engine nobody UNCO --- 2019-04-04
1537879 Gecko content processes on Android run at a lower priority level than the parent process GeckoView General nobody RESO DUPL 2019-04-03
1537951 Too many unknown threads in the parent process of FXR GeckoView General nobody RESO FIXE 2019-04-12
1538053 Schedule nursery GC and slices around requestAnimationFrame Core JavaScript: GC nobody NEW --- 2021-04-27
1538250 see if we can avoid initializing nsiCertStorage on the main thread (or open the backing db off the main thread) Core Security: PSM dkeeler RESO FIXE 2019-03-29
1538364 Consider firing the load/loadend/final readyState events for XHR later during page load (after page load event if possible) Core DOM: Networking bugs RESO FIXE 2019-06-09
1538784 Set nsThreadPool limits more intelligently Core XPCOM nobody NEW --- 2019-03-29
1539053 Rotating and/or moving text in creating a new story is very slow and choppy. Core Canvas: 2D nobody NEW --- 2020-08-28
1539266 Running gfxPlatform::Init in the content process can take a long time Core Graphics nobody NEW --- 2019-03-29
1540026 RTX On/Off comparison on nvidia.com runs at a drastically lower FPS in Firefox than in Chrome Core Graphics nobody UNCO --- 2020-08-30
1540080 JetStream 2 bomb-workers test much slower in Firefox than Chrome and Safari Core DOM: Workers amarchesini RESO FIXE 2019-10-28
1540226 Brief video and audio interruptions on YouTube when tab is focused after it was in the background Core Graphics nobody NEW --- 2019-05-15
1540388 So much CPU usage running Firefox, the fan is at maximum Core Performance nobody RESO WORK 2020-02-19
1540683 Investigate performance impact of tuning the number of SSL Cert threads on low-end hardware Core Performance sefeng NEW --- 2019-11-14
1540777 Fresh profile page load regressions from enabling LSNG on Mar 8th, 2019 Core Storage: localStorag jvarga RESO FIXE 2021-05-17
1540917 With strict content-blocking, course pages at business.unsw.edu.au trigger a content-process hang (with error-handling recursion death-spiral, in site's JS) Web Compatibility Desktop nobody NEW --- 2021-01-29
1542263 2.61 - 5.65% Heap Unclassified / Images (linux64-shippable, linux64-shippable-qr, windows10-64-shippable, windows7-32-shippable) regression on push 60c20a0f320cc769a8da229cdf6edfbbf38d3ed3 (Wed Apr 3 2019) Core CSS Parsing and Comp emilio RESO WORK 2020-05-06
1542995 Thousands of window.onload events creates high memory/CPU until it crashes Core General nobody NEW --- 2020-03-05
1543403 Normandy hangs the browser UI for over one second when verifying signatures Firefox Normandy Client dkeeler RESO FIXE 2019-12-18
1543409 Wix editor is extremely slow in Firefox Core JavaScript Engine nobody NEW --- 2019-07-24
1543776 [meta] 5+ second delays seen while loading www.allrecipes.com on geckoview_example Core Performance nobody NEW --- 2021-01-25
1543783 m.facebook.com live site loads 1s slower in Fenix/GVE than Fennec 64 Core Performance sefeng ASSI --- 2021-05-01
1543806 Incremental GC can block off-thread parsing Core JavaScript: GC mgaudet RESO FIXE 2020-09-02
1544091 my cpu is 10-15 degrees hotter on firefox (55...60C) than on google chrome (45..50C) Core Performance nobody UNCO --- 2020-01-16
1544369 3.28 - 4.65% sessionrestore / startup_about_home_paint (linux64-shippable, windows10-64-shippable, windows10-64-shippable-qr) regression on push 6534d80a3329536b4bb9068f9d56ccb030616750 (Fri Apr 12 2019) Firefox Search nobody NEW --- 2019-12-11
1545034 Significant increase of loading times on CodiMD caused with bug 1504947 Core JavaScript Engine nobody RESO FIXE 2019-05-15
1545578 Investigate loading early libraries with RTLD_DEEPBIND for WebRender talos wins Core Graphics: WebRender nobody NEW --- 2020-09-06
1546313 YouTube with Polymer v3.2.0 is loading slower than with Polymer v1.x Core JavaScript Engine nobody RESO FIXE 2019-05-23
1546513 Closing the network panel with many entries takes multiple seconds DevTools Netmonitor odvarko RESO FIXE 2019-05-31
1546752 Stop creating .metadata files Core Storage: Quota Manag shes050117 RESO FIXE 2019-06-12
1546847 Multi-second UI jank/freeze when serializing SessionStore data over to the SessionFile worker Firefox Session Restore dothayer ASSI --- 2021-05-24
1547688 LSNG: Preloading can use gUsages hash table to quickly finish if there's nothing to preload Core Storage: localStorag jvarga RESO FIXE 2019-05-08
1547997 Increase network.http.max-connections on android (currently 20) Core Networking acreskey RESO FIXE 2019-06-28
1548185 use a smarter heuristic for when to run the next iGC slice Core JavaScript: GC nobody RESO INVA 2020-11-16
1548539 Stopping blocking bfcache on unconnected peerconnections Core WebRTC nobody NEW --- 2019-05-08
1548824 2.21% tscrollx (windows10-64-shippable-qr) regression on push 09753a1a153d348d456a0c785fcffeb9a77dd065 (Wed May 1 2019) Core Graphics: WebRender nobody NEW --- 2019-11-15
1550073 [meta] GeckoView startup performance GeckoView General nobody NEW --- 2021-03-22
1550511 Slow interaction with interactive lichess analysis graph (inline SVG in a document with slow-to-reflow grid and flex ancestors) Core Layout nobody RESO FIXE 2020-07-15
1550531 -moz-element leaks memory and hangs whole browser with massive CPU usage at closing browser window with large image Theme after landing patch from bug #1330487 Core SVG jwatt VERI FIXE 2019-05-28
1550535 Mark <svg> elements (nsSVGOuterSVGFrame) as reflow roots Core Layout dholbert RESO FIXE 2019-06-29
1550579 On Fenix (Arm32) ec_Curve25519_mul() takes a surprising amount of time NSS Libraries kjacobs.bugzilla RESO FIXE 2019-08-14
1550754 ContentParent::KillHard janks the main thread during startup Toolkit Crash Reporting nobody RESO WORK 2020-04-27
1551122 Performance regression when running JS benchmark Core Performance nobody UNCO --- 2019-07-16
1551313 Add profiler markers for preference reads Core Preferences: Backend whawkins RESO FIXE 2020-03-10
1551547 Twitch on Firetv/GV falls behind and stops playing video on busy channels (4k stick) Core Performance nobody RESO INCO 2020-07-21
1551890 68ms used to GetHWEncoderCapabilities() during Fenix startup Core Audio/Video chris RESO FIXE 2019-05-17
1552003 Scrolling very laggy on good hardware since update a few weeks ago (current FF 66), profile attached Core Graphics nobody UNCO --- 2019-12-02
1552132 Some devices run arm64 JS+wasm x10 slower than arm firefox or arm64 webview Core Javascript: WebAssem nobody RESO FIXE 2021-04-21
1552183 getSystemColors sometimes takes up to 800ms in GeckoView/Fenix startup Core Performance whawkins RESO INVA 2019-05-31
1552348 Investigate if canceling ion compilation because of GC adds noise to Speedometer and elsewhere, and if so, figure out how to not cancel ion. Core JavaScript Engine: J nobody NEW --- 2019-07-23
1552356 CSS Named Color "hue vs luminosity" chart demo is much slower in Firefox than in Chrome (with time spent in JS math code) Core JavaScript Engine: J nobody NEW --- 2019-07-08
1553074 WebRender is using too much CPU (Radeon HD 6900? Lots of BG tabs?) Core Graphics: WebRender nobody NEW --- 2020-11-21
1553399 Firefox start slowly when started through ProfileManager (ProfileManager doesn't unlock the mutex dir before launching the child) Toolkit Startup and Profile dothayer RESO FIXE 2021-04-29
1553842 the URL classifier should not attempt an update on every Gecko startup - especially on Android Toolkit Safe Browsing nobody RESO DUPL 2019-10-11
1553867 Time spent in ClonePrincipalForPermission() during pageload Core DOM: Core & HTML amarchesini RESO FIXE 2019-09-25
1553959 Site with filters (https://www.scandinavianphoto.se/) takes longer to load in Fennec than in Chrome/Safari Core Graphics nobody RESO WORK 2021-04-21
1553980 Defer initial processing by Privileged Content process at startup Firefox New Tab Page nobody NEW --- 2020-08-20
1554075 Twitch.tv buffer appends cause frame drops on HD8 in GeckoViewExample. Core Audio/Video: Playbac chris RESO FIXE 2019-07-02
1554183 Initializing platform fonts at startup on MainThread is taking a long time in GeckoView (~220ms on G5) Core Graphics rjesup RESO FIXE 2019-08-26
1554242 Sending a blob to a content process does main thread I/O Core DOM: File dothayer RESO FIXE 2019-09-19
1554313 Classifier Update should wait for an user-idle period before initiating an update Toolkit Safe Browsing nobody NEW --- 2020-11-02
1554395 StartupCache takes a very long time to write out cache after browser startup Core XPCOM nobody NEW --- 2019-11-25
1554930 Potential impact of the ever-growing HSTS preload list Core Security Block-lists nobody RESO WORK 2019-08-03
1555306 Collision on NS find_objects()/sqlite3PagerSharedLock() when fetching OSCP causes extereme variance in page load times Core Security: PSM rjesup NEW --- 2019-09-23
1555404 [meta] Support dynamic TLS cipher suites Core Security: PSM nobody NEW --- 2020-02-28
1555407 [meta] Improve default TLS performance on ARM32 NSS Libraries nobody NEW --- 2020-03-03
1555522 Enable JavaScript Startup Bytecode Cache for DevTools code Core JavaScript Engine nobody NEW --- 2019-06-03
1555726 Using Firefox on Windows 10 makes Conexant audio driver's Flow.exe program use excessive CPU Core Audio/Video nobody RESO DUPL 2020-03-20
1555801 SSL Cert threads and the Socket Thread can fight over find_objects() and the sqlite3PagerSharedLock Core Security: PSM nobody RESO DUPL 2019-06-14
1556022 speedof.me reports download speeds for Geckoview_example and Fenix to be ~40% to 50% of Chrome's - Moto G5 Core Graphics nobody RESO WORK 2021-04-21
1556104 Long paints occurring in the PaintThread causing slow tab switches / tab switch spinners Core Graphics nobody RESO WORK 2019-07-10
1556243 Reddit CSS for classicwow subreddit causes severe performance issues Core Graphics: WebRender aosmond RESO FIXE 2019-07-15
1556263 Abnormally high CPU usage on Firefox 67 running on MacOS 10.14 Core Performance nobody UNCO --- 2020-06-22
1556476 Periodic delays for 1.5 seconds Core Performance nobody RESO INCO 2019-12-30
1556815 High CPU usage when browsing LinkedIn on Linux Core Performance nobody UNCO --- 2019-07-16
1557447 Profiler support for IPC information (Gecko side) Core Gecko Profiler jporterbugs RESO FIXE 2021-02-01
1557505 ECPoint_mul/ec_points_mul take a lot of time on Arm32 NSS Libraries nobody NEW --- 2021-04-27
1557765 Bad performance instantiating class with constructor Core JavaScript Engine: J andrebargull RESO FIXE 2020-06-15
1558080 Degraded performance with CSS animations Core Graphics nobody RESO WORK 2021-04-21
1558170 Firefox freezes for 10 to 15 seconds every so often while working with Android Studio Core Performance nobody UNCO --- 2019-09-25
1559438 Switching to "Tags" in Reply by Buffer hangs the process (slow querySelectorAll) Core CSS Parsing and Comp nobody NEW --- 2019-07-18
1561095 [Fission] Seeing a lot more tab spinners of doom Core Performance nobody RESO DUPL 2020-11-23
1562544 Already running Firefox Hangs for 2-3 minutes and all tabs refresh after starting any v8 Javascript Engine based product Core Performance nobody RESO DUPL 2019-11-15
1563208 Going to ntv.com.tr, page does not load quickly and all other tabs stopped responding Core Layout nobody RESO WORK 2020-07-17
1565144 FirefoxCP Web Content memory leak with every refresh with devtools DevTools Inspector nobody RESO DUPL 2021-01-21
1565701 Firefox making more HTTP requests than Chrome when loading https://ebay.com Core Networking sefeng RESO DUPL 2019-08-12
1566322 Firefox takes a long time to load pages Core Networking: DNS nobody RESO INCO 2019-09-10
1566945 pass line box through from nsTextFrame::SetLength to nsBlockFrame::AddFrames Core Layout: Block and In dbaron RESO FIXE 2019-07-18
1567018 [DoS/Hang] Firefox still hangs on wake up from OS X Power Nap (even with AppNap disabled via 1551990) Toolkit Storage nobody NEW --- 2021-01-04
1567556 Slack "Add reaction" search popup flashes blue alt text before loading emoji images Core DOM: Service Workers nobody NEW --- 2020-08-04
1567626 enqueueSetState takes a lot longer time than Chrome on ARM devices Core JavaScript Engine nobody NEW --- 2019-07-25
1567718 FF appears frozen while examining fonts on startup after OS update (due to DWrite caches being cold) Core Layout: Text and Fon nobody NEW --- 2020-10-21
1567863 Firefox startup slow - window loads quickly, but first network call delayed, works normal after that Core Networking nobody NEW --- 2021-05-01
1567977 Scrolling sometimes reacts late on touch input on Android Core Panning and Zooming nobody NEW --- 2021-02-10
1568027 WebRender performs worse on Binding of Isaac CodePen demo (svg filters/blob) Core Graphics: WebRender nobody NEW --- 2020-12-11
1568029 Slow script dialog from Scratch Core JavaScript: GC jcoppeard RESO FIXE 2019-08-15
1568058 Long delay when using Phaser to load an audio sprite, works fine in Chrome Core Audio/Video: Playbac mfroman VERI FIXE 2020-10-20
1568730 Content process stalls in SyncObjectD3D11Client::Synchronize during startup Core Graphics: Layers mconley NEW --- 2019-12-03
1568760 1.54 - 1.73% Base Content JS (linux64-shippable, linux64-shippable-qr, macosx1014-64-shippable, windows10-64-shippable, windows10-64-shippable-qr, windows7-32-shippable) regression on push 1e0a350b954aa03edffbbd391116a0ecc01da647 (Fri July 19 2019) Core JavaScript: Internat andrebargull RESO FIXE 2020-10-13
1569412 Firefox 68 on wife's MacBook Air 2015 macOS 10.14.5 is getting dreadfully slow and no way to find out why Core Performance nobody NEW --- 2019-09-27
1570090 Investigate fast first paints Core Performance bugs NEW --- 2020-05-30
1570144 CSS animation codepen demo locks up browser (possibly whole OS?) Core Graphics: Layers nobody RESO WORK 2021-04-26
1570192 New-tab page has some kinda-slow synchronous flexbox/grid layout Firefox New Tab Page dholbert VERI FIXE 2019-08-13
1570296 [Meta] Allow dynamically set higher priority of IPC messages of the same type (e.g. for navigation start) Core Performance nobody NEW --- 2021-05-21
1570313 speedof.me reports download speeds for Geckoview_example and Fenix to be ~40% to 50% of Chrome's - Moto G5 Core Networking: HTTP m_kato RESO FIXE 2020-01-08
1570417 Consider using line cursor for nsBlockFrame::AddFrames Core Layout nobody NEW --- 2019-08-01
1570619 2.44% tart (windows10-64-shippable) regression on push a91cc939f11246643f966e61a7bfa58d8a11a237 (Wed June 26 2019) Firefox Build System Task Configuration nobody RESO WONT 2019-11-05
1570664 Consider speculatively loading redirections Core Performance rjesup NEW --- 2020-04-30
1570747 UrlClassifierFeatureBase::InitializePreferences took a long time during page load Toolkit Safe Browsing nobody RESO DUPL 2019-09-26
1570750 gfxFontGroup::FindFontForChar took a lot of time during reflow Core Layout: Text and Fon nobody NEW --- 2021-04-22
1570752 Logging code in child process takes significant amount time GeckoView General nobody RESO INVA 2021-02-09
1570770 Incremental reflows on New-tab page are showing up in profiler Core Layout nobody NEW --- 2019-08-01
1570921 1.28 - 1.51% Base Content JS (linux64-shippable, linux64-shippable-qr, macosx1014-64-shippable, windows10-64-shippable, windows10-64-shippable-qr, windows7-32-shippable) regression on push 6c3d3ce32b08ef2f55d75ffe1a19d60b13c11341 (Mon July 29 2019) Core JavaScript: Internat andrebargull RESO FIXE 2019-11-06
1571238 Slow-ish style time with tons of custom elements and rules. Core CSS Parsing and Comp nobody NEW --- 2019-08-08
1571286 Firefox won't able to handle requests correctly this leads to slow down or crash the browsers DevTools Console nobody NEW --- 2020-07-02
1571301 Refresh driver keeps firing at 60fps unnecessarily on this page Core Performance nobody RESO WORK 2021-03-05
1571479 Jank and high CPU usage for tens of seconds, after opening a bunch of new tabs (with browser.tabs.remote.separatePrivilegedContentProcess = true) Firefox New Tab Page mconley VERI FIXE 2020-04-13
1571800 Tons of time spent on the main thread when animations are accelerated in nsIFrame::IsScrolledOutOfView. Core CSS Transitions and nobody NEW --- 2019-08-21
1572180 68 runs 3x slower than 67 on sample script Core Performance nobody NEW --- 2020-08-06
1572538 Running ExtensionProcessScript.jsm during page load takes significant amount time WebExtensions General nobody NEW --- 2021-05-04
1572540 GV should disable logging by default in opt GV builds GeckoView General nobody NEW --- 2020-01-14
1572674 2.29% ts_paint (windows10-64-shippable-qr) regression on push 9d66a096d9e2872c33798b7633448b9144298885 (Sat August 3 2019) Firefox Build System Toolchains nobody RESO DUPL 2020-08-05
1573137 User reported extreme Android battery consumption - Firefox for Android 68.0 Core Performance nobody NEW --- 2020-01-20
1573294 Firefox high CPU usage when loading a tab with a large site (reddit comments) Core Performance nobody RESO INCO 2019-11-14
1573542 Slow performance (switching tabs, interacting with map) on this map Core Security: PSM dkeeler VERI FIXE 2019-12-16
1574024 ARM64 - 10% page load regression on reddit with Ion enabled Core JavaScript Engine: J nobody RESO FIXE 2021-04-22
1574445 9.04 - 9.2% tp5n nonmain_startup_fileio (windows7-32-shippable) regression on push e966b7945f692c8957c498ff6d063036d01d60a1 (Tue August 6 2019) Testing Performance standard8 RESO WONT 2020-06-30
1575216 nsAvailableMemoryWatcher::Notify hangs in K32GetPerformanceInfo Core Widget: Win32 gsvelto RESO FIXE 2019-10-04
1575315 FF appears frozen while examining fonts loading smile.amazon.com (looking for codepoint U+FFFE) Core Layout: Text and Fon jfkthame RESO FIXE 2019-09-19
1575610 Determine cause for increase in number of Nightly users seeing short tab switch spinners starting August 9th, 2019 Firefox Tabbed Browser dothayer RESO FIXE 2019-09-23
1575818 3.91 - 21.86% raptor-ares6-firefox / raptor-tp6m-amazon-search-geckoview-cold loadtime (android-hw-g5-7-0-arm7-api-16, linux64-shippable, linux64-shippable-qr) regression on push 9ef1dcfda500b98dbea2e921e0a103e795a59703 (Tue August 13 2019) Core JavaScript: GC jcoppeard RESO FIXE 2020-03-31
1576202 Page load performance regressions with baseline interpreter enabled on Pixel 2 Core JavaScript Engine: J nobody RESO INVA 2019-08-28
1576404 wizard of oz easter egg incredibly slow in Firefox Core Graphics nobody NEW --- 2019-09-13
1576549 mozilla::a11y::ProxyAccessible::Bounds is slow on GeckoView when clicking date field on hotels.com Core Disability Access AP eitan RESO FIXE 2019-09-02
1577631 Slow loading compare to Chrome on deploy-preview-194--firefox-performance-dashboard.netlify.com Core Performance nobody RESO DUPL 2019-09-05
1578227 Loading arewefastyet.com can sometimes be very slow Core Networking nobody NEW --- 2021-04-21
1578884 Opening menu is slow on salsitasoft.com on Firefox for Andoid, MacOS Core Graphics: WebRender nobody NEW --- 2020-10-22
1578991 9.17 - 16.31% raptor-tp6-twitch-firefox (windows10-64-shippable) regression on push b3ee5fed44ec711f79202150223cda9397c6ed80 (Wed August 14 2019) DevTools JSON Viewer sstreich RESO FIXE 2019-10-31
1579185 Google Maps on a clean profile locks the tab and takes ~2 min to show any content Core Performance nobody RESO WONT 2019-11-14
1579596 Keyboard input is extremely laggy on twitter.com Core Layout: Flexbox nobody RESO WORK 2020-03-27
1580016 High CPU Usage of "Web Content" and "WebExtensions" when chrome or VSCode open Core Graphics: Text nobody RESO DUPL 2019-11-23
1580117 [macOS] High CPU utilization with restored minimized windows Core Graphics jryans VERI FIXE 2020-12-11
1580656 Do not scan for new fonts so aggressively on Linux Core Graphics: Text nobody NEW --- 2020-01-24
1581130 Some periodic job in Mozilla Firefox keeps one CPU core 100% occupied for long periods of time Core Networking dd.mozilla ASSI --- 2021-05-24
1581296 Freeze / terrible performance with the attached test case Core Layout: Block and In nobody NEW --- 2019-09-17
1581978 High GPU on elements with multiple shadows Core Graphics nobody NEW --- 2019-09-25
1582525 Avoid racing 6 connections for sites known to have been HTTP2 in the past Core Networking nobody NEW --- 2019-09-25
1583217 Visual metrics: Fenix is significantly slower than Chrome for the site https://m.imdb.com Core Performance sefeng RESO FIXE 2021-04-21
1583220 Visual metrics: Fenix is significantly slower than Chrome for the site https://cnn.com Core Performance sefeng NEW --- 2021-05-20
1583222 Visual metrics: Fenix is significantly slower than Chrome for the site https://www.reddit.com Core Performance sefeng NEW --- 2021-05-20
1583228 Visual metrics: Fenix is significantly slower than Chrome for an amazon search Core Performance sefeng RESO FIXE 2021-04-21
1583230 Visual metrics: Fenix is significantly slower than Chrome for the site https://booking.com Core Performance sefeng RESO FIXE 2021-04-21
1583298 Determine if we are indeed spending up to 3x as long in DNS resolution as Chrome on some sites Core Performance nobody NEW --- 2021-04-16
1583927 Firefox has 100% CPU usage. Core Performance nobody NEW --- 2020-12-10
1584418 High CPU usage on Firefox likely due to hidden loading spinners Core SVG nobody NEW --- 2021-04-07
1585327 Add normal-priority event queue delay time to Responsiveness measurements Core Performance rjesup NEW --- 2019-11-21
1587040 VSync firing 255 times more frequently than normal during "display off" sleep on Windows Core Graphics nobody NEW --- 2020-10-23
1587058 Remove ChromeUtils.idleDispatch from the critical path for intercepted web requests WebExtensions General tomica RESO FIXE 2021-04-28
1587759 2.97 - 146.11% raptor-tp6-* regression on push be9a6289486a6f366e431782b84a0c0633f8fec2 (Wed October 9 2019) Core DOM: Service Workers echuang RESO FIXE 2020-03-18
1588003 Text animation is slow Core Graphics nobody NEW --- 2020-08-28
1589085 Protocol and MIME info handler service access in the child process causes synchronous IPC Firefox File Handling nobody NEW --- 2019-11-07
1589294 CSS animation on a children node of a parent element with visibility:hidden, opacity: 0 raises CPU Core Layout nobody RESO FIXE 2020-05-07
1589788 Page becomes unresponsive on victoriassecret.com Core JavaScript Engine nobody RESO WORK 2021-04-21
1591030 Images flash when returning to a tab Core ImageLib nobody NEW --- 2020-04-17
1591090 Consider using a hash table in NotifyVisited. Toolkit Places emilio RESO WORK 2020-04-24
1591343 CPU time utilization tab hangs. The tab does not respond. Core XML nobody REOP --- 2021-02-04
1591366 Bad performance with deeply-nested display: grid elements Core Layout: Grid sefeng ASSI --- 2021-05-21
1592366 YouTube live streaming is janky and sometimes the image would freeze completely. Core Performance nobody NEW --- 2019-10-31
1592975 2.99 - 8.02% raptor-tp6-instagram-firefox-cold / raptor-tp6-instagram-firefox-cold fcp / raptor-tp6-twitch-firefox fcp (linux64-shippable, linux64-shippable-qr) regression on push e66da643d9bcbc594a9c09a99271ae4d9415e388 (Wed October 30 2019) Core DOM: Security sstreich RESO INVA 2020-05-19
1593876 hanging + keyboard malfunction Firefox Session Restore nobody UNCO --- 2019-11-15
1593994 Very slow text input Core Performance nobody UNCO --- 2021-02-23
1596238 Iterating DOM Nodes is 40% - 50% slower than Chrome using NodeIterator with a filter which doesn't find any nodes Core DOM: Core & HTML bugs RESO FIXE 2019-12-05
1596634 When blur filter is applied on a large area, it delays the full rendering Core Graphics nobody NEW --- 2020-12-09
1596784 Support SetTimeout deferral during load in Fission Core DOM: Content Process rjesup RESO FIXE 2021-01-26
1596844 Update toolchains to include workarounds for Intel JCC Erratum performance degradation Firefox Build System Toolchains nobody RESO FIXE 2021-04-21
1597522 Gmail login page loading is slower than Chrome Core JavaScript Engine nobody NEW --- 2021-04-30
1597601 Change EventQueue implementation to reduce allocation churn of Queue buffers Core XPCOM rjesup RESO FIXE 2019-11-21
1597817 Page load slows down UI interactions on certain old Linux machines Core Performance nobody RESO INVA 2020-01-10
1598356 Very long main-thread hangs when visiting YouTube in Nightly launched from DMG image - blocked launching the RDD process Core Audio/Video: Playbac nobody NEW --- 2021-03-24
1598384 13 seconds of jank when loading https://data.firefox.com/dashboard/hardware Core JavaScript Engine nobody NEW --- 2019-12-05
1599216 Huge GUI lag when adjusting SVG Core Graphics nobody NEW --- 2020-02-13
1599246 New tabs are unresponsive after unlocking session Core Performance nobody RESO WORK 2020-01-06
1599472 Stream the output of inflate in nsHTTPCompressConv::OnDataAvailable out to another thread to be converted to UTF16 when possible Core DOM: Networking nobody NEW --- 2019-11-28
1599489 For large json payloads, convert to UTF16 off the main thread Core DOM: Networking nobody NEW --- 2019-11-28
1599508 Enabling Safebrowsing is introducing significant noise in network throttled pageload tests Core Performance acreskey NEW --- 2019-11-28
1599811 Lag/freezing when switching tabs Firefox Messaging System andrei.br92 RESO FIXE 2020-01-13
1600418 Delay during switching tabs (after long browsing session) Firefox Untriaged nobody RESO INVA 2019-12-10
1601237 Frequent hangs in debugger code DevTools Debugger nobody RESO WORK 2020-12-03
1602018 Fission content process startup is slowing down pageload Core DOM: Navigation nobody RESO FIXE 2020-07-22
1602025 Browsing from about:blank to a URL runs activity-stream code and does an about:newtab reflow Firefox New Tab Page nobody NEW --- 2020-02-24
1602099 180ms main thread jank in the parent process due to regular expressions in Blocklist.jsm Toolkit Blocklist Implementa nobody RESO FIXE 2020-01-10
1602434 FileChannel::MakeFileInputStream does mainthread IO via nsIFile::IsDirectory Core Networking: File nobody NEW --- 2020-11-06
1602506 Visual metrics: Fenix is slower than Fennec for the site www.bing.com Core Performance nobody NEW --- 2019-12-16
1602508 Visual metrics: Fenix is slower than Fennec for the site www.youtube.com/watch?v=COU5T-Wafa4 Core Performance nobody NEW --- 2020-03-02
1602510 Visual metrics: Fenix is slower than Fennec for the site https://stackoverflow.com/questions/927358/how-do-i-undo-the-most-recent-commits-in-git Core Performance nobody NEW --- 2020-02-28
1602513 Visual metrics: Fenix is slower than Fennec for the site booking.com Core Performance nobody NEW --- 2020-02-19
1602578 Certain sites use a large amount of memory, sometimes over 1 GB Core Performance nobody UNCO --- 2020-02-26
1602757 Fission content processes aren't prestarted Core DOM: Navigation rjesup RESO FIXE 2020-07-17
1602818 NavigationStart (and thus 'loadtime') for a page doesn't start until the content process is started in Fission Core DOM: Navigation nobody RESO FIXE 2020-07-15
1602842 OSXDisplay::EnableVsync hangs in CVDisplayLinkCreateWithActiveCGDisplays Core Widget: Cocoa nobody NEW --- 2021-02-20
1603276 `toLocaleTimeString` allocate massive amounts of memory DevTools Netmonitor bugzilla RESO FIXE 2020-01-14
1603302 Slow layout on longer WebSocket tables DevTools Netmonitor nobody NEW --- 2020-01-09
1603404 Performance change between Firefox 70 and Firefox 71 Wikipedia Core Graphics: Text nobody RESO WONT 2021-04-29
1603578 Implement caching of retired web-isolated processes for reuse in the same domain in Fission Core DOM: Navigation nobody NEW --- Fri 18:35
1603853 Ensure parent process triggers speculative connection when possible. GeckoView General nobody RESO INVA 2020-01-22
1604077 Firefox Hangs Repeatedly Loading Some Sites Core DOM: Device Interfac nobody UNCO --- 2021-04-30
1604252 Visual metrics: Fenix is slower than Fennec for the site m.facebook.com Core Performance nobody NEW --- 2020-03-02
1604253 Visual metrics: Fenix is slower than Fennec for the site tripadvisor.com Core Performance nobody NEW --- 2020-02-19
1604255 Visual metrics: Fenix is slower than Fennec for the site abcnews.go.com Core Performance nobody NEW --- 2019-12-16
1604256 Visual metrics: Fenix is slower than Fennec for the site https://people.com/amp-stories/royal-a-to-z Core Performance nobody NEW --- 2020-02-19
1604257 Visual metrics: Fenix is slower than Fennec for the site https://www.bing.com/search?q=restaurants Core Performance nobody RESO INVA 2020-02-13
1604258 Visual metrics: Fenix is slower than Fennec for the site https://zalando.de/herrenschuhe/?exclusive=true Core Performance nobody RESO INVA 2020-02-19
1604260 Visual metrics: Fenix is slower than Fennec for the site accounts.google.com Core Performance nobody RESO FIXE 2021-03-29
1604261 Visual metrics: Fenix is slower than Fennec for the site https://zalando.de Core Performance nobody RESO INVA 2020-02-19
1604262 Visual metrics: Fenix is slower than Fennec for the site https://cnn.com/ampstories/us/why-hurricane-michael-is-a-monster-unlike-any-other Core Performance nobody RESO INVA 2020-02-13
1605513 Slashdot tab has consistently high energy impact (score of >19) Core Performance nobody NEW --- 2020-10-09
1606652 Off thread parse scripts as soon as they are fetched Core Performance dpalmeiro RESO FIXE 2020-09-15
1606992 Having a Master Password makes Firefox password manager (both Lockwise and legacy) slow to load (10s for 300 passwords on an i7), using 100% CPU and causing laptop fans to spin up NSS Libraries kaie VERI FIXE 2020-02-05
1607590 Test rel=preload impact on mobile page load Core Performance rjesup RESO FIXE 2020-10-23
1607890 Slow paints in visbug Core Graphics: WebRender nobody NEW --- 2020-08-19
1607986 Clicking "play" on paper.io is extremely slow on Firefox, smooth on Chrome Core JavaScript Engine: J evilpies RESO FIXE 2020-05-30
1608289 More GC's occurring during parsing in Fenix compared to Fennec 68 Core JavaScript: GC nobody NEW --- 2020-03-05
1608290 JS parsing (and possibly execution) slower in Fenix vs Fennec Core JavaScript Engine nobody NEW --- 2020-06-08
1608826 [meta] Geckoview load initiation performance GeckoView General nobody NEW --- 2021-04-21
1609206 We need Performance testing builds for mozilla-central Firefox Build System General nobody NEW --- 2020-04-02
1609478 Avoid doing large memsets to poison values (or to 0, etc) under the memory lock Core Memory Allocator rjesup NEW --- 2020-08-26
1609682 preload required content and master-process scripts at startup of GeckoView GeckoView General nobody NEW --- 2021-02-16
1609936 Requests get redirected in parent intercept mode with a service worker that doesn't listen to fetch events Core DOM: Service Workers nobody RESO DUPL 2020-02-03
1610147 25ms paints on Twitter with WebRender when refreshing for latest posts Core Web Painting nobody RESO WORK 2020-10-22
1610904 Slowdown and performance issues on Reddit.com new design Core Performance nobody RESO DUPL 2021-04-30
1611820 Minimize time spent loading modules in chromeutils.import when starting a first-time load GeckoView General bdahl RESO FIXE 2020-04-21
1612355 Render/Layout-Performance Issues with Grid-Layout Core Layout: Grid nobody NEW --- 2020-05-13
1612365 Moving specific map is extremely slow to unusable Core Performance nobody RESO FIXE 2020-05-22
1612575 Experiment with speculative connections in Geckoview or consuming apps GeckoView General nobody RESO FIXE 2021-01-07
1613205 Visual metrics: Fenix is slower than Fennec for the site google.com Core Performance mstange.moz RESO WONT 2021-04-21
1613473 Fenix is slower to load nytimes.com then other browsers GeckoView General nobody RESO WORK 2020-02-26
1613760 [fission-power] Synchronize periodic background tasks (such as expiration tracker ticks) across content processes Core Performance nobody NEW --- 2021-02-05
1613824 Apple Newsroom page takes a long time to load (30 seconds) Core Performance nobody NEW --- 2020-06-22
1614096 [meta] Move all devtools UI out of the parent process into a privileged content process DevTools General nobody NEW --- 2021-01-17
1614415 High CPU/janky performance when dragging on Tradingview charts Core Performance nobody NEW --- 2020-02-28
1614425 https://www.fido.ca/ Pages load on mobile is several seconds slower than chrome Core Performance nobody NEW --- 2020-02-28
1617497 animations on svg polygons perform better on Chrome than Firefox Core SVG nobody NEW --- 2021-04-07
1618391 Avoid parsing and compiling self-hosted code during startup (takes 90ms on Android Moto G5) Core JavaScript Engine nobody NEW --- 2021-05-17
1619032 Preferences initialization spends 100ms in NotifyCallbacks on a Moto G5 Core Preferences: Backend mstange.moz RESO FIXE 2020-03-19
1619141 poll widget on tagesspiegel.de very laggy Core Graphics nobody NEW --- 2020-03-13
1619796 Don't fire `onLoadRequest()` for loads initiated via `GeckoSession.loadUri()`. GeckoView General agi RESO FIXE 2020-03-24
1620079 Large amounts of time are spent in module import when starting Fenix (applink) GeckoView General nobody NEW --- Thu 09:54
1620111 Avoid synchronous ReadFontList IPC message Core Layout: Text and Fon jfkthame RESO FIXE 2020-03-09
1620445 Share omni.ja memory between processes on Android Toolkit Startup and Profile nobody NEW --- 2021-04-21
1621021 Running Basemark Web 3.0 test in a background tb seems to bog down the compositor Core Graphics nobody NEW --- 2020-05-11
1621340 GeckoView startup causes SafeBrowsing to re-initialize multiple times because it flips pref after SafeBrowsing.init(), taking an extra 130ms GeckoView General droeh RESO FIXE 2020-08-05
1621366 simpleperf for android has recording gaps Core Performance acreskey RESO FIXE 2020-04-27
1622455 Firefox tab freezes when a huge log is displayed on Github Actions Core Performance nobody UNCO --- 2020-04-17
1622721 Slow performance when scrolling Firefox subreddit top posts of the week Core Performance nobody NEW --- 2021-01-10
1623408 Restoring Previous Session is sluggish Core Performance nobody UNCO --- 2020-10-21
1623518 Script cache information from the content process is never written to disk in GeckoView (10-20ms startup penalty for uncached script loading) GeckoView General nobody NEW --- 2021-04-21
1623758 Disable APK compression for the omnijar for a potential 440ms startup win (on Moto G5) GeckoView General agi RESO FIXE 2020-03-25
1623988 Freezes on inspect html and when html node is opened DevTools Inspector razvan.caliman RESO FIXE 2021-01-20
1624348 SCROLL_PRESENT_LATENCY reports times longer than 10 minutes Core Performance nobody NEW --- 2020-05-11
1624846 autocomplete.js is excessively slow - only in Firefox Core DOM: Core & HTML jdai ASSI --- 2020-06-15
1624959 Fenix opens the verge articles 2x as slow as Bromite Core Performance nobody RESO DUPL 2020-04-08
1625499 Very high heap-unclassified memory usage GeckoView General nobody RESO DUPL 2020-08-10
1626132 Ghost-Windows from reddit Core Performance nobody NEW --- 2020-07-08
1626263 High CPU load while waiting for a page to load (MacOS) Core Graphics nobody UNCO --- 2020-05-11
1626389 Sync IPC message GetShowPasswordSetting() sent during page load, please remove GeckoView General m_kato RESO FIXE 2020-04-22
1626719 Firefox Nightly hangs when displaying a Grafana Core JavaScript Engine nobody NEW --- 2021-04-08
1626789 Firefox becomes extremly unresponsive when doing local gecko build in parallel Core Performance nobody NEW --- 2021-01-25
1626816 WebRender program cache / shader initialization blocks the main thread via the sync IPC message PWebRenderBridge::EnsureConnected (25ms-40ms startup penalty) Core Graphics: WebRender nobody NEW --- 2020-05-11
1627039 Long (~250ms) GCRuntime::gcCycle pauses on the new Facebook site Core JavaScript: GC jcoppeard RESO FIXE 2020-05-04
1627273 firefox is very slow and crashes because of p11-kit-proxy.so Core Security: PSM nobody RESO WORK 2020-12-07
1627453 Layers hardware acceleration causing high memory consumption on theguardian.com Core Graphics nobody RESO WORK 2021-04-21
1627458 Bad performance around covid map on theguardian.com Core Graphics: WebRender nobody RESO WORK 2021-04-21
1627522 Slow File Upload on YouTube Core Networking dd.mozilla RESO INAC 2021-02-24
1628220 Middle button actions slow when primary selection belongs to a remote process Core Widget: Gtk nobody UNCO --- 2020-11-05
1628449 GeckoSession.loadUri() doesn't complete until future loop iteration GeckoView General snorp RESO FIXE 2020-04-09
1629649 Excessive memory usage on 32gb machine Core Performance nobody NEW --- 2021-03-27
1630442 Slow loading and closing of reddit posts on Moto G (XT1031) Core CSS Parsing and Comp nobody REOP --- 2021-03-17
1630737 Main-thread in the parent process blocked while viewing Amazon when using several recommended add-ons from AMO WebExtensions General tomica RESO DUPL 2020-04-28
1630999 webRequest overhead for data: urls from about:newtab Firefox New Tab Page mconley NEW --- 2020-05-19
1631520 Developer tools inspector is very slow on YouTube DevTools Inspector nobody RESO DUPL 2020-04-29
1631714 Firefox causes 10% CPU load even when doing nothing Core Performance nobody RESO INVA 2020-06-12
1633318 "mozStorage #6" thread using 100% CPU Toolkit Places nobody NEW --- 2020-11-26
1634437 Call nsLookAndFeel::EnsureInit() before MSG_ConstructBrowser is received for new processes Core Widget: Gtk sefeng RESO FIXE 2020-12-07
1634707 platzi.com - slow website dialog Web Compatibility Desktop nobody RESO WORK 2020-08-07
1635642 firefox is very poor at managing memory. Why would it need to use 4GB of memory with a few tabs? Core Performance nobody RESO INCO 2021-02-17
1635979 Slow page loading on YouTube Core Networking nobody RESO WORK 2020-06-16
1636067 Memory leak when open about:preferences. Core Internationalization nobody RESO DUPL 2020-07-07
1637425 Slow script warning with Slack Core Performance nobody RESO DUPL 2020-07-01
1637567 high CPU processor usage in firefox-v61 Core Performance nobody UNCO --- 2020-06-04
1637606 HTML Based Speed Tests Produce Slower Results or Fail Core Performance nobody UNCO --- 2021-02-23
1637735 [Github] Very slow page loading on reddit (around 4x slower than Chromium) Core JavaScript Engine nobody NEW --- 2021-03-30
1637802 Add markers for script compilation and execution Core Performance dpalmeiro RESO FIXE 2020-05-24
1637863 Game play gets really slow when getting to a certain level Firefox General nobody RESO WONT 2020-05-25
1638058 Enable video in a Google Meet call makes Nightly stutter and hang. Core WebRTC nobody NEW --- 2021-04-21
1638119 Allow extension processes to be preallocated Core DOM: Navigation nobody NEW --- 2020-05-31
1639280 Unacceptable performance and memory consumption on Apart Posters VR experience. Core Canvas: WebGL nobody NEW --- 2020-10-05
1639740 Deselecting rows in gsheets takes 1s+ main thread plus severe delay Core JavaScript Engine nobody NEW --- 2020-05-22
1640535 severe input lag when using multiple keyboards under linux(X11) Core Performance nobody UNCO --- 2020-12-17
1641696 Firefox takes 50% more time than Microsoft Edge to display first paint of comments in reddit posts Core Networking nobody NEW --- 2021-05-04
1641724 Since updating Firefox Nightly after the Memorial Day weekend, browser is unstable and locks up Core Performance nobody NEW --- 2021-05-07
1642415 Memory leak and high CPU when opening prefs/options/settings or on startup, due to language packs matching build locales with older translations that lack some strings causing excessive locale loading Core Internationalization nobody NEW --- 2021-03-23
1642780 EasyEDA PCB designer extremely slow (skia vs. D2D difference in svg paths) Core Graphics nobody UNCO --- 2020-07-30
1642950 Opening browser console is very slow DevTools Console nobody NEW --- 2021-05-13
1643064 Memory leak in foreground webworker Core JavaScript: GC nobody NEW --- 2020-07-14
1643226 [performance] Very high CPU usage and slow scrolling Core Performance nobody NEW --- 2021-01-09
1643560 High memory usage on Facebook Core JavaScript Engine nobody UNCO --- 2021-01-14
1643800 raptor-tp6-reddit-firefox load time on Linux is noisier and about 0-20% slower with Fission than non-Fission Core DOM: Content Process nobody RESO WORK 2020-07-20
1643801 raptor-tp6-fandom-firefox load time on Linux is 5% slower with Fission than non-Fission Core DOM: Content Process rjesup RESO WONT 2021-01-26
1643802 raptor-tp6-imgur-firefox load time is slower with Fission than non-Fission (200% on Linux and 20% on Windows) Core DOM: Content Process nobody RESO WONT 2021-01-26
1643805 raptor-tp6-netflix-firefox load time is slower with Fission than non-Fission (10% on Linux and 60% on Windows) Core DOM: Content Process rjesup VERI WORK 2021-01-26
1644041 Closing a tab in FF 77 leaves a spot for several seconds before the tabs are resized, other UI parts become unresponsive as well Firefox Tabbed Browser nobody RESO WONT 2020-07-08
1644811 connectStart on live sites (measured in Fenix) has regressed ~20ms in the period May 02 to May 29 Core Performance acreskey NEW --- 2020-06-10
1645606 On Windows 10 on VirtualBox on MAC OS X, Guest OS hangs after firefox 75 Core Performance nobody RESO INVA 2020-09-08
1646222 Google Sheets hangs for 3-10 seconds after maximizing or unmaximizing browser window Core Graphics: WebRender emilio VERI FIXE 2020-11-20
1646449 Background tabs stuck loading while CPU is under heavy load Core Performance nobody NEW --- 2020-07-09
1646496 Memory leak degradation Core Performance nobody NEW --- 2020-07-21
1646799 setInterval(..., 0) is not clamped, unlike setTimeout(..., 0) Core DOM: Core & HTML bugs RESO FIXE 2020-08-06
1646976 High CPU load on macOS during file download Firefox Downloads Panel nobody NEW --- 2021-05-18
1647153 Slow reloading of Pocket Explore on Moto G (XT1031) Core Performance nobody NEW --- 2021-04-29
1647161 Make Win32 nsWindow cloaking-aware on Windows 8+ Core Widget: Win32 nobody NEW --- 2020-06-24
1647847 Huge lag typing into a slack popup Core JavaScript Engine nobody NEW --- 2020-06-25
1648233 High CPU usage by idle Firefox Core Performance nobody NEW --- 2020-06-30
1648793 Stuttering while scrolling on dual displays with game or video playing in one screen (Nvidia 2070, 2x 1440p@144hz) Core Performance nobody NEW --- 2020-07-07
1649052 Scrolling on LineageOS download page spends 70ms-140ms in Layout (The scrolling itself is smooth) Core Layout: Flexbox nobody RESO WORK 2021-03-20
1649890 High CPU use on Techradar Core Performance nobody NEW --- 2020-10-21
1649892 High CPU use on Whathifi Core Performance nobody RESO WORK 2020-10-21
1650063 Loading https://www.worldometers.info/coronavirus/#countries is occasionally slow, takes lots of time in query_selector_slow Core CSS Parsing and Comp nobody NEW --- 2021-01-06
1650250 Slow startup/high CPU use when restoring Firefox session with about:newtab as active tab in all windows Firefox Session Restore nobody NEW --- 2021-01-21
1650288 lazy-loading images performances for small images Core Performance nobody NEW --- 2020-07-24
1650708 Firefox takes 50% more time than Chrome to load/reload pages on Boardgamegeek Core Performance nobody NEW --- 2020-07-24
1650896 High memory usage after skipping an ad on YouTube Core Performance nobody RESO INCO 2021-03-01
1652048 Potentially unnecessary idle tasks queued for background processes via PerformanceCounters Core Performance nobody NEW --- 2021-02-12
1652793 Firefox gradually becomes slower to respond, until it becomes completely unresponsive Core Performance nobody NEW --- 2020-08-21
1653056 [meta] Fission tp6 page load is slower than non-Fission on some sites Core Performance rjesup RESO WONT 2021-01-26
1653088 Performance issue on voice.google.com - Site can hang from seconds to minutes Core JavaScript: GC nobody NEW --- 2020-08-11
1653777 WebGL aquarium sample runs at 30 FPS on Google Pixel 2, 60 FPS on WebView/Chromium Core Canvas: WebGL nobody NEW --- 2021-02-16
1653779 Firefox freezes and becomes unusable on react/typescript/eval-source-map project DevTools Debugger wartmanm ASSI --- Thu 06:37
1653809 Firefox taking up CPU (fans going crazy) on realsimple.com Core Layout nobody NEW --- 2021-02-01
1654087 reddit.com: slow page performance after scrolling through a lot of pages Core General nobody NEW --- 2021-04-30
1654178 [Fission?] Lag while switching tabs Core Graphics: WebRender nobody RESO WORK 2020-09-23
1655580 Fenix leaks 7MB (heap-unclassified) every time the browser app is foregrounded GeckoView General mstange.moz VERI FIXE 2020-08-25
1655683 nsRFPService::ReduceTimePrecisionImpl is slow Core Security nobody RESO FIXE 2021-04-21
1655751 Large and slow web page on re:dash Core CSS Parsing and Comp emilio RESO FIXE 2020-10-07
1655777 Extremely laggy typing on Facebook replies (nsRFPService::ReduceTimePrecisionImpl is slow) Core Security nobody RESO WORK 2020-08-27
1656386 Slow loading of Medium article on Moto G (XT1031) Core Performance nobody NEW --- 2020-07-31
1656709 some games at gamee.com stutter a lot on firefox while it's smooth on chrome Core Canvas: 2D nobody NEW --- 2020-10-26
1657183 Janking/stuttering while scrolling on imgur (Celeron N4000) (Geminilake) Core Graphics nobody NEW --- 2021-01-27
1657651 Loading issue when first launching Firefox 79 Core DOM: Service Workers nobody NEW --- 2020-11-17
1658202 Massive slowdowns when downloading to samba share Core DOM: Core & HTML gijskruitbosch+bugs RESO FIXE 2020-11-01
1659286 Jank when closing tabs in a full tab bar from session restore Core Performance nobody NEW --- 2020-09-08
1659359 Heavy janking while doing page up/down on while loading a few tabs in the background Core Performance nobody NEW --- 2020-10-21
1659831 Geektyrant takes 4x as long as Chrome to load Core Layout: Grid nobody NEW --- 2020-08-28
1660184 FireFox 78 x64 and newer on Windows after a while becomes slow Core Performance nobody UNCO --- 2020-09-20
1660475 slow websites on many tabs (3000+) Core Performance nobody UNCO --- 2021-01-21
1660838 LinkedIn - high resource use (aka fans go crazy) on MacOS Core Performance nobody NEW --- 2020-09-24
1660890 Significant regression in Fenix, Desktop pageload performance Core Performance acreskey RESO FIXE 2020-09-01
1661054 Keeping the web console open in a background tab causes the refresh driver to tick continously at 60Hz DevTools Console florian RESO FIXE 2021-02-26
1661090 browser and content hangs when zooming map at https://mrosd.maps.arcgis.com/apps/webappviewer/index.html Core Graphics nobody NEW --- 2020-10-05
1661311 30 second browser hang on Google Docs Core Graphics emilio RESO FIXE 2020-10-26
1661491 Frame dropping due to GC when looking at https://arewefenixyet.com Core JavaScript: GC nobody NEW --- 2021-03-15
1661554 piece selection/movement on lichess not as smooth as on chrome Core Performance nobody RESO INVA 2020-09-20
1661594 Firefox 79.0.5 struggles with reddit videos. Core Performance nobody REOP --- 2020-09-22
1661941 WebBrowserPersistSerialize actor does mainthread IO Core DOM: Core & HTML nobody NEW --- 2020-09-24
1662252 eightsleep.com is much slower (7-10s) to paint in Firefox than Chrome (1-3s) Core Audio/Video: Playbac nobody NEW --- 2020-09-07
1662811 Inconsistent & fluctuating FPS on webgl based sites Core Canvas: WebGL nobody UNCO --- 2021-01-08
1662825 Poor performance and call terminated during a Google Meet call Core Graphics: WebRender nobody NEW --- 2021-05-25
1663360 Choppy Animation of Pie and Line chart during page load Core JavaScript Engine nobody UNCO --- 2020-09-23
1664067 Mac OSX, 10.14.6 FireFox 80.1 hangs for minutes on some sites>>>>>> it was working but now that you have upgraded firefox to 81.0 it is back Core Performance nobody RESO DUPL 2021-03-02
1664492 Extremely long DNS resolution times with Fenix Core Networking: DNS nobody NEW --- 2020-09-24
1665736 uBlock Origin slows down page loads on Galaxy m21 Core Performance nobody NEW --- 2020-09-18
1665910 Firefox 80: Loading pages is often extremely slow Core Performance nobody NEW --- 2021-04-28
1666139 performance issues during startup Core Performance nobody UNCO --- 2020-10-27
1667246 Fenix loads apple.com 2 seconds slower than Chrome Core Performance nobody NEW --- 2021-05-07
1667248 Fenix loads cloudflare.com 5 seconds slower than Chrome Core Performance nobody NEW --- 2020-10-02
1667250 Fenix loads adobe.com 4 seconds slower than Chrome Core Performance nobody NEW --- 2021-05-07
1667316 RedirectSink cyclic reference doesn't get dropped Core Networking: HTTP valentin.gosu NEW --- 2021-04-21
1669009 Fenix loads images a second slower than SmartCookieWeb on low end tablet Core Performance nobody RESO WONT 2021-04-21
1669046 Sluggish page and menus on wayfair.com (poor responsiveness) Core Performance nobody RESO WORK 2021-01-20
1669307 Investigate relaxing windows timer granularity, especially on battery, to reduce energy use Core XPCOM nobody NEW --- 2020-10-09
1670190 Increased redirectEnd metric in Firefox 80 when connecting to Jira Core Performance nobody UNCO --- 2020-12-16
1671859 Not responding notification from Firefox (in titlebar) when switching to a background window Core Graphics nobody NEW --- 2021-02-02
1673418 Firefox hangs when clicking linkedin.com links from Slack comment Core Layout nobody RESO DUPL 2021-03-29
1673988 Laggy Performance in bartamanpatrika.com in fenix Core Performance nobody NEW --- 2020-10-29
1675628 Checkerboarding on scrolling wired.com article Core Performance nobody NEW --- 2020-11-21
1676210 High memory and CPU usage on www.tvnow.de with garbage collector involved Core XPCOM nobody NEW --- 2020-12-11
1676799 Scrolling in firefox on Android, clicking a link has become slow; have to click a link twice or thrice to open Core Performance nobody UNCO --- 2021-02-18
1676889 http requests to localhost ports where nothing is listening take longer to fail than in blink Core Networking nobody NEW --- 2021-01-28
1677351 Poor WebRender graphics performance in Nightly 84 on GNOME w/ Wayland Core Graphics: WebRender nobody RESO INVA 2020-11-22
1677501 PK11_ListCerts called by DoHHeuristics.jsm during late startup does a lot of main thread I/O to cert9.db Core Networking: DNS valentin.gosu RESO FIXE 2020-12-01
1677509 SendReceiveMouseInputEvent often blocks the main thread of the parent process Core Panning and Zooming dothayer ASSI --- 2021-05-19
1677516 cert_storage blocks the parent process main thread Core Security: PSM dkeeler RESO FIXE 2020-12-08
1677569 CYCLE_COLLECTOR_MAX_PAUSE regression on May 11, 2020 Core XPCOM nobody NEW --- 2021-04-21
1678446 Slow page loading/rendering after upgrading to MacOS 11.0.1 Big Sur with blocked Socket thread, and "close" system calls taking one second each Core Networking nobody RESO INVA 2020-12-04
1678512 Firefox slowing down to a crawl when using Whatsapp Web for several days Core Performance nobody UNCO --- 2020-12-29
1678643 Very bad browser jank due to CRLite Core Security: PSM nobody RESO DUPL 2020-12-08
1678715 Very unresponsive content process, with a page using SMIL animations in the background Core SVG nobody NEW --- 2020-12-13
1679088 High CPU usage (WindowServer) on macOS Big Sur Core Performance nobody NEW --- 2021-05-14
1679309 More checkerboarding than Edge on politico.com, on a two core machine Core Performance nobody NEW --- 2020-12-19
1679770 Add improved telemetry for paint responsiveness Core Performance nobody NEW --- 2020-12-17
1679863 HTMLCanvasElement.getContext is slow Core Security: Process Sa gpascutto NEW --- 2020-12-17
1680860 [meta] Performance investigations surrounding large IndexedDB responses Core Storage: IndexedDB nobody NEW --- 2021-05-04
1681043 mozilla::PDMFactory::Supported blocks the main thread when creating the first content process during startup Core Audio/Video: Playbac jya-moz VERI FIXE 2021-02-03
1681088 Consider making speculative connections to minimize redirection time Core Performance nobody NEW --- 2020-12-17
1681614 [Bug] High memory consumption, os paging, with a certain url Core Performance nobody RESO WORK 2021-01-22
1681984 L10nMutations::FlushPendingTranslations() can block the UI when a macbook goes out of sleep Core Internationalization gtatum NEW --- 2021-03-23
1682043 Entering fullscreen marks all tabs loaded in the parent process as visible Core Graphics emilio RESO FIXE 2021-05-05
1682163 Excessive memory use causing Firefox Quantum and other app crashes Core Graphics: WebRender nobody NEW --- 2021-03-23
1682261 http://www.jabra.com.de claims up to 20% CPU load as background tab or when Firefox is hidden Core Audio/Video: Playbac alwu NEW --- 2021-01-12
1682986 Choppy Canvas2D on Android on this page Core Canvas: 2D nobody NEW --- 2021-01-29
1683250 Laggy swipes on swiperjs.com Core Graphics: WebRender nobody NEW --- 2021-02-16
1683300 [meta] High CPU load (40% - 100%) caused by the top extensions loading animation on https://code.visualstudio.com/docs/ Core Graphics: WebRender nobody NEW --- 2021-02-22
1683354 [Bug] Scrolling stutter on gadgets.ndtv.com website Core Graphics: WebRender nobody NEW --- 2021-04-28
1683560 Huge performance regression in webgame on https://project-f.github.io Core Performance nobody NEW --- 2021-05-20
1683975 Opening a new tab on Big Sur is delayed by 100ms due to system font initialization Core Graphics: WebRender mstange.moz ASSI --- 2021-01-27
1684139 High CPU use on sports.williamhill.com due to unclamped setInterval(f, 0) in worker Core DOM: Workers echuang VERI FIXE 2021-03-19
1684636 Poor performance on jackbox.tv (radial gradients) Core Graphics: WebRender nobody RESO FIXE 2021-04-05
1685798 Focusing the summary text field on Bugzilla janks for one second Toolkit Form Autofill nobody NEW --- 2021-04-26
1685835 Too many tabs of one site can cause Firefox to lag Core Performance nobody NEW --- 2021-03-18
1686094 freezing on Facebook website with other tabs in the background Core Performance nobody UNCO --- 2021-02-18
1686592 Responsiveness: On Twitter, switching from Home to Explore takes 2.5x as long as in Chrome Core JavaScript Engine: J nobody NEW --- 2021-02-10
1686696 timeupdate event is fired possibly too often Core Audio/Video alwu RESO FIXE 2021-02-17
1686794 Really late inputs on Facebook messenger Youtube Twitch Core JavaScript Engine nobody NEW --- 2021-05-25
1687535 Accessibility gets initialized by unsupported interfaces for example on windows touch screen and related devices Core Disability Access AP bas RESO FIXE 2021-02-18
1688943 Consider converting timestamps in PerformanceResourceTiming and PerformanceNavigationTiming on creation Core Performance mstange.moz ASSI --- 2021-02-24
1688951 Lazy font loading can still hang the main thread on Windows Core Layout: Text and Fon nobody NEW --- 2021-04-29
1689156 Slow tab switching on pages with long-running requestAnimationFrame handlers, like Slack Firefox Tabbed Browser sefeng RESO FIXE 2021-03-26
1689215 20% CPU overhead in the native event loop from CA::Transaction::observer_callback(__CFRunLoopObserver*, unsigned long, void*) Core Widget: Cocoa nobody NEW --- 2021-05-22
1689225 Low FPS Scrolling on Touchpad (Windows 4k) Core Graphics: WebRender nobody NEW --- 2021-04-29
1689703 Fission visual metrics regression on Mac for Microsoft Core Performance nobody RESO FIXE 2021-03-01
1689746 Slow scrolling on weather.com today page Core Graphics: WebRender gwatson NEW --- 2021-04-21
1690654 Detect no-op renders during frame building and avoid the render, to reduce power usage Core Graphics: WebRender nobody NEW --- 2021-03-03
1690690 Unnecessary ChildToParentMatrix messages during animations Core Graphics nobody NEW --- 2021-02-25
1691190 With ublock installed, it looks like the webext process spends 100s of ms in GC right after startup Core JavaScript: GC nobody NEW --- 2021-02-27
1691813 Browser hangs for a few seconds when scrolling and right-clicking on a view source tab after session restoration Core Disability Access AP nobody NEW --- 2021-05-18
1692035 Opening a new browser window feels slow Core Performance nobody NEW --- 2021-03-09
1692828 Scrolling lags due to long composites on mac Core Graphics: WebRender nobody NEW --- 2021-05-25
1693176 CSS animations in hidden panels cause the refresh driver to keep ticking Core DOM: Animation emilio ASSI --- 2021-03-03
1694126 Drafting longer e-mails in outlook.office.com frequently freezes / slowdowns, due to spell check / ProofingPlugin.js? Core Performance nobody UNCO --- 2021-05-12
1694417 Slow reflow when selecting a large amount of text Core Layout: Text and Fon nobody NEW --- 2021-03-09
1694420 Opening large data URLs in a new tab is very slow to display text in URL bar Core Layout: Text and Fon nobody NEW --- 2021-03-19
1695439 FireFox using too much RAM Core Performance nobody UNCO --- 2021-03-01
1695717 Unexpectedly long delay when searching via Google and HTTP/3 enabled Core Networking dd.mozilla VERI FIXE 2021-04-16
1696171 Navigation on YouTube and YouTube Music gets CPU to 100% Core Performance nobody REOP --- 2021-05-09
1696853 Slow performance when Win10 speech recognition is enabled Core Performance nobody UNCO --- 2021-03-09
1697218 Significant cold pageload regression see on Fenix live site tests Core Performance acreskey RESO DUPL 2021-04-29
1698855 Poor performance when Telegram and Google Chat web clients are in use. Core Performance nobody NEW --- 2021-05-11
1699376 Google sheet loading hangs with half of the screen black Core JavaScript Engine: J nobody NEW --- 2021-04-07
1699500 Slow restyles on chat.google.com Core CSS Parsing and Comp nobody NEW --- Tue 15:51
1699501 Slow reflow on chat.google.com, with deeply nested flexbox Core Layout: Flexbox nobody NEW --- 2021-04-30
1700377 Consider auto-terminating slow scripts if they are running in a process only serving ads Core XPConnect nobody NEW --- 2021-04-08
1701484 HSL color demo spends large time in nested grid reflow, when you drag a slider to adjust a color Core Layout: Grid nobody NEW --- 2021-03-29
1701956 Scrolling twitter has more checkerboarding than Chrome Core JavaScript Engine nobody NEW --- 2021-04-16
1704812 Broadcast new FontList shm blocks to Content Processes instead of waiting and doing sync IPC Core Layout: Text and Fon jfkthame RESO FIXE 2021-05-13
1706333 122.22 - 2.73% cnn-ampstories FirstVisualChange / ebay ContentfulSpeedIndex + 22 more (Windows) regression on Fri April 16 2021 Firefox Theme nobody NEW --- Thu 09:20
1708042 Consider to have very high priority ("control") for DidComposite tasks Core Performance bugs RESO FIXE Tue 23:39
1708488 Initialize NSS in preallocated processes, before RecvConstructBrowser Core DOM: Content Process sefeng RESO FIXE 2021-05-14
1710869 Ensure certs are sent to the content process and decoded as early as possible for preallocated process Core DOM: Content Process nobody NEW --- 2021-05-13
1711758 More aggressively abort slow scripts when the tab (browser/docshell) goes away Core DOM: Navigation nobody NEW --- Thu 09:52
1712882 Opening a ticket in JIRA from a kanban board is slow Core JavaScript Engine nobody NEW --- Fri 10:36
1776 bugs found.
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