Closed Bug 1572222 Opened 5 years ago Closed 5 years ago

Regression: More slow frames appearing on pages that did not previously have slow frames

Categories

(Core :: Graphics: WebRender, defect, P3)

Desktop
All
defect

Tracking

()

RESOLVED FIXED
mozilla71
Tracking Status
firefox-esr60 --- unaffected
firefox-esr68 --- unaffected
firefox68 --- unaffected
firefox69 --- unaffected
firefox70 --- wontfix
firefox71 --- fixed

People

(Reporter: yoasif, Assigned: sotaro)

References

(Blocks 1 open bug, Regression)

Details

(Keywords: nightly-community, regression)

Attachments

(2 files)

Noticed that I was seeing many more additional slow frames in the latest build.

STR:

  1. Enable gfx.webrender.debug.slow-frame-indicator
  2. Navigate to https://bugzilla.mozilla.org/show_bug.cgi?id=1562433
  3. Scroll down page.

What happens:

Slow frame indicator moves a lot.

Expected result:

Few slow frames.

8:04.11 INFO: Last good revision: 7ef78f0d0e04e153ea887f1923c9fe5075be8551
8:04.11 INFO: First bad revision: 267e2feb994ff4a42a5ead26873b2f2047a57bb5
8:04.11 INFO: Pushlog:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=7ef78f0d0e04e153ea887f1923c9fe5075be8551&tochange=267e2feb994ff4a42a5ead26873b2f2047a57bb5

Blocks: slow-frames
Has Regression Range: --- → yes
Has STR: --- → yes
Regressed by: 1570869
Flags: needinfo?(mstange)
Hardware: Unspecified → Desktop

Thanks for the report!

I'm not sure if this means that we're actually slower on these pages or if I just did something that affected the indicator.
Sotaro, do you have any quick ideas what I could have broken? I'm happy to back out the patches unless you think this is "expected".

Flags: needinfo?(mstange) → needinfo?(sotaro.ikeda.g)

just chiming in that I just updated nightly on my macbook pro and am also seeing this now (it is extremely distressing after being so conditioned to associate movement with badness)

Attached image profiler-screenshot.png

It looks like it's just the indicator/fps metric that's busted. Everything still feels buttery smooth but basically any interaction trips the indicator (async scrolling on bugzilla, moving the mouse over a button, etc).

Attached: screenshot of the profiler from about a minute of just moving my mouse around about:config. The individual metrics seem to clearly suggest everything is running buttery smooth, but the actual FPS and frame indicator disagree.

edit: whoops forgot to enable the GPU metrics -- they show about 5ms GPU time on average, so still fine.

Keywords: perf
OS: Unspecified → All

(In reply to Markus Stange [:mstange] from comment #1)

Sotaro, do you have any quick ideas what I could have broken? I'm happy to back out the patches unless you think this is "expected".

I wonder if https://phabricator.services.mozilla.com/D40371 might be related. mRenderingCount was incremented synchronously. With the change the count is update on Render thread. It might cause TooManyPendingFrames() == true more often.

Priority: -- → P3
Pushed by sikeda.birchill@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/c12928fd9352
Revert TooManyPendingFrames() logic r=nical
Status: NEW → RESOLVED
Closed: 5 years ago
Resolution: --- → FIXED
Target Milestone: --- → mozilla71
Assignee: nobody → sotaro.ikeda.g
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