1566901 - Picture caching doesn't work anymore on http://diana-adrianne.com/purecss-francine/

Status: RESOLVED FIXED

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

Description

[Jeff Muizelaar [:jrmuizel]]

STR:

• turn on gfx.webrender.debug.picture-caching.
• load http://diana-adrianne.com/purecss-francine/
• observe a bunch of red when scrolling

I believe this used to work.

Comment 1

[Jeff Muizelaar [:jrmuizel]]

It worked better around 2019-02-01

Comment 2

[Jeff Muizelaar [:jrmuizel]]

I started on a regression window but didn't finish:
https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=848ce760ba38b646edf21040f6dbb1c1b7fd4ba2&tochange=69628e2c8fd19479d7ec64de4c9694c845497083

Comment 3

[Darkspirit]

mozregression --good 848ce760ba38b646edf21040f6dbb1c1b7fd4ba2 --bad 69628e2c8fd19479d7ec64de4c9694c845497083 --pref gfx.webrender.all:true gfx.webrender.debug.picture-caching:true -a http://diana-adrianne.com/purecss-francine/

https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=855d557b82a20e1ed87af46bceac3b918534d37e&tochange=431c5142ff3ad102328d90cb29470b20ccd1271e

431c5142ff3ad102328d90cb29470b20ccd1271e Glenn Watson — Bug 1558106 - Support picture caching for multiple scroll roots. r=kvark

Comment 4

[Glenn Watson [:gw]]

It seems that during scrolling some of the primitive descriptors get assigned a different number of active / valid clips. There might be other reasons it is getting incorrectly invalidated, but I'll start with looking into that.

Comment 5

[Glenn Watson [:gw]]

Attachment: Bug 1566901 - Make picture caching more robust to float issues.

This patch fixes a couple of picture caching issues that could
cause more invalidations than required. Specifically:

• Ensure the viewport rect is included in child surfaces, so
  that redundant clips are filtered out correctly.
• Use epsilon comparisons where appropriate for tile descriptor
  comparisons, to avoid invalidations due to float inaccuracies.

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/121b5b367241
Make picture caching more robust to float issues. r=kvark,nical

Comment 7

[Noemi Erli[:noemi_erli]]

https://hg.mozilla.org/mozilla-central/rev/121b5b367241

Comment 8

[Glenn Watson [:gw]]

Comment on attachment 9078965 [details]
Bug 1566901 - Make picture caching more robust to float issues.

Beta/Release Uplift Approval Request

• User impact if declined: Some pages fail to hit the picture caching fast path, which can cause noticeable page rendering slowness on WebRender.
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: Yes
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): It's a relatively simple / small patch. Only affects users enrolled in WebRender.
• String changes made/needed:

Comment 9

[Ryan VanderMeulen [:RyanVM]]

Comment on attachment 9078965 [details]
Bug 1566901 - Make picture caching more robust to float issues.

Fixes some slowdowns with WebRender enabled. Approved for 69.0b8.

Comment 10

[Andrei Ciure[:aciure]]

https://hg.mozilla.org/releases/mozilla-beta/rev/c134c5e050d8

Comment 11

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

Backed out as https://hg.mozilla.org/releases/mozilla-beta/rev/c4fa4d3613fb2a9d2ee9ae139a1fbe5ada22b072 and relanded with correct commit information: https://hg.mozilla.org/releases/mozilla-beta/rev/79459ea654f59e741de12f491d62e0e9b003cc52