Closed Bug 1635569 Opened 3 years ago Closed 3 years ago

Properly set flags on dlls opened and mapped for prefetching

Categories

(Toolkit :: Startup and Profile System, enhancement)

Product:
Toolkit
Component:
Startup and Profile System
Type:
enhancement

Tracking

()

Status:
RESOLVED FIXED
Milestone:
mozilla78
Tracking Flags:
Tracking Status
firefox78 --- fixed

People

(Reporter: dthayer, Assigned: dthayer)

References

(Blocks 1 open bug)

Details

(Whiteboard: [fxperf])

Attachments

(1 file)

Bug 1635569 - Set execute flags when prefetching images r?aklotz
47 bytes, text/x-phabricator-request
Details | Review

This is not documented, but there's strong reason to believe that our flags aren't quite right WRT prefetching images. See https://chromium-review.googlesource.com/c/chromium/src/+/1534983/17/base/files/memory_mapped_file_win.cc#23 - committed by a Microsoft engineer.

Blocks: 1627071

This is plausibly affecting the performance of our reads against xul.dll. I started looking through chrome's prefetching code after I noticed (comparing procmon logs of firefox vs chrome startup) chrome.dll prefetching showed reads of 1MiB in length, whereas we just read single pages. Also possibly unrelated. Need to test.

Pushed by dothayer@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/875ebbd9a1c9
Set execute flags when prefetching images r=aklotz

https://hg.mozilla.org/mozilla-central/rev/875ebbd9a1c9

Status: NEW → RESOLVED
Closed: 3 years ago
status-firefox78: --- → fixed
Resolution: --- → FIXED
Target Milestone: --- → mozilla78
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