1911450 - Opening reddit posts spends a lot of time on the parent process Part2 (Followup to bug 1907701)

Status: NEW

(Core :: Performance, defect)

Description

[Mayank Bansal]

https://bugzilla.mozilla.org/show_bug.cgi?id=1907701#c11

(In reply to Markus Stange [:mstange] from comment #11)

It would have been better if that patch had landed in a new bug. Oh well.
Mayank, can you open a new bug for the remaining slowness? Thank you.

---

STR:

Create a new profile OR use your existing profile.
Go to https://www.reddit.com/r/AgeofMythology/new/
Open some posts in the background tab (either by middle clicking on the post, or by Right click->Open link in new tab)
Maybe scroll a little

AR: Jank
Profile: https://share.firefox.dev/3Yv8LqF, https://share.firefox.dev/3WLyJoG,

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:dimi, could you have a look please?

For more information, please visit BugBot documentation.

Comment 2

[Markus Stange [:mstange]]

Here's how the 33118 Runnable markers from the first profile (https://share.firefox.dev/3Yv8LqF) break down:

33118 counts
(  1)     3029 ( 9.1%,  9.1%): DNSListenerProxy::OnLookupComplete
(  2)     2380 ( 7.2%, 16.3%): net::CacheFileChunk::Release
(  3)     1606 ( 4.8%, 21.2%): net::ExecuteCallback
(  4)     1553 ( 4.7%, 25.9%): MozPromise::ThenValueBase::ResolveOrRejectRunnable
(  5)     1511 ( 4.6%, 30.4%): AsyncUrlChannelClassifier::CheckChannel - return
(  6)     1488 ( 4.5%, 34.9%): asyncOnChannelRedirect/<[WebRequest.sys.mjs]:JS
(  7)     1488 ( 4.5%, 39.4%): nsAsyncRedirectVerifyHelper
(  8)     1488 ( 4.5%, 43.9%): nsAsyncVerifyRedirectCallbackEvent
(  9)     1203 ( 3.6%, 47.5%): FeatureHolderRelease
( 10)     1203 ( 3.6%, 51.2%): UrlClassifierLookupCallbackProxy::LookupCompleteRunnable
( 11)      801 ( 2.4%, 53.6%): net::CacheEntry::StoreFrecency
( 12)      772 ( 2.3%, 55.9%): ProxyReleaseEvent for nsInterfaceRequestorAgg::mFirst
( 13)      762 ( 2.3%, 58.2%): PNecko::Msg_PHttpChannelConstructor
( 14)      762 ( 2.3%, 60.5%): net::ContinueAsyncOpenRunnable
( 15)      760 ( 2.3%, 62.8%): net::HttpBackgroundChannelParent::ActorDestroy
( 16)      744 ( 2.2%, 65.1%): PFetchEventOp::Msg___delete__
( 17)      744 ( 2.2%, 67.3%): PFetchEventOp::Reply___delete__
( 18)      743 ( 2.2%, 69.6%): observeActivity/<[SearchSERPTelemetry.sys.mjs]:JS
( 19)      709 ( 2.1%, 71.7%): CacheFileInputStream::NotifyListener
( 20)      697 ( 2.1%, 73.8%): PNecko::Msg_PredLearn

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

This bug was moved into the Performance component.

:mayankleoboy1, could you make sure the following information is on this bug?

• ✅ For slowness or high CPU usage, capture a profile with http://profiler.firefox.com/, upload it and share the link here.
• For memory usage issues, capture a memory dump from about:memory and attach it to this bug.
• Troubleshooting information: Go to about:support, click "Copy raw data to clipboard", paste it into a file, save it, and attach the file here.

If the requested information is already in the bug, please confirm it is recent.

Thank you.

Comment 4

[Mayank Bansal]

Profile from latest Nightly (containing the fix from bug 1594368) : https://share.firefox.dev/48twj2o

Comment 5

[Mayank Bansal]

Attachment: lots of js.zip

Stress test with 1000 CSS files and 3000 js files.

• Profile when served over a local server: https://share.firefox.dev/4f5tw1A
• Profile when served over a local server (with uBlock): https://share.firefox.dev/3C6XKCX
• (Less interesting)Profile when opened directly: https://share.firefox.dev/3YMvdub

Comment 6

[Bas Schouten (:bas.schouten)]

The Performance Impact Calculator has determined this bug's performance impact to be high. If you'd like to request re-triage, you can reset the Performance Impact flag to "?" or needinfo the triage sheriff.

Platforms: Windows
Impact on site: Causes noticeable jank
Websites affected: Major
[x] Able to reproduce locally

Comment 7

[BugBot [:suhaib / :marco/ :calixte]]

The severity field for this bug is set to S3. However, the Performance Impact field flags this bug as having a high impact on the performance.
:fdoty, could you consider increasing the severity of this performance-impacting bug? Alternatively, if you think the performance impact is lower than previously assessed, could you request a re-triage from the performance team by setting the Performance Impact flag to ??

For more information, please visit BugBot documentation.

Comment 8

[Frank Doty [:fdoty]]

Unable to reproduce locally with several Reddit - needs more testing. Reducing this to Med and S2 until more information is collected and discussed