1674396 - (sw-wr-perf-clip-box-shadow) High memory and CPU usage during video playback on Twitch with webrender software fallback

Status: RESOLVED FIXED

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

Description

[Maja Frydrychowicz :impossibus (was :maja_zf) (needinfo me)]

Perhaps this is expected with webrender.software=true? My laptop fans go wild as soon as I start playing a video on Twitch. I do not get the same fan noise when I watch a long YouTube video, say.

I recorded two performance profiles under pretty much the same conditions (fresh profile, the Nightly versions are different but close together). In both cases, the steps during the recording are:

1. Navigate to Twitch page - video autoplays
2. Let it play for a while
3. Navigate to firefox.com

https://profiler.firefox.com/from-addon/calltree/?globalTrackOrder=7-8-9-0-1-2-3-4-5-6&hiddenGlobalTracks=1-2-3-4-5&localTrackOrderByPid=215284-1-2-0~215319-0~215702-0~216635-0~215397-0~215445-0~216532-0-1~&thread=7&v=5

https://profiler.firefox.com/from-addon/calltree/?globalTrackOrder=8-9-10-0-1-2-3-4-5-6-7&hiddenGlobalTracks=1-2-3-4-5-6&localTrackOrderByPid=219252-1-2-0~219282-0~219813-0~219773-0~219491-0~219320-0~219398-0~219683-0-1~&thread=8&v=5

Comment 1

[Jeff Muizelaar [:jrmuizel]]

It looks like you didn't publish the profiles. Can you gather some new ones and publish them?

Comment 2

[Maja Frydrychowicz :impossibus (was :maja_zf) (needinfo me)]

D'oh! Sorry.

Now I get "Error publishing" on profiler.firefox.com. Maybe it's too big? I'll try again on Monday.

Comment 3

[Maja Frydrychowicz :impossibus (was :maja_zf) (needinfo me)]

https://share.firefox.dev/34MBJpU

https://share.firefox.dev/321nb3O

Comment 4

[Jeff Muizelaar [:jrmuizel]]

It looks like those profiles were taken with screenshots turned on. Can you redo them with "Firefox Graphics" preset?

Comment 5

[Maja Frydrychowicz :impossibus (was :maja_zf) (needinfo me)]

Now with the graphics preset:

https://share.firefox.dev/2JyBgQ5

https://share.firefox.dev/2HX804E

Comment 6

[Jeff Muizelaar [:jrmuizel]]

What resolution are you running at?

Comment 7

[Maja Frydrychowicz :impossibus (was :maja_zf) (needinfo me)]

I think 3840 x 2160 but I don't have access to the system in question anymore.

Comment 8

[Lee Salzman [:lsalzman]]

It looks like perhaps the most actionable thing here is the time spent in cs_clip_box_shadow. Most everything else is hitting fast-paths.

Comment 9

[Lee Salzman [:lsalzman]]

Attachment: Bug 1674396 - Implement SWGL fast-path for box shadows. r?jrmuizel

This adds a span shader that tries to treat the box shadow as a nine-patch
and intersect with the various sectors of it. This allows committing entire
contiguous spans of texture from the source box shadow rather than doing
slower per-fragment processing.

Comment 10

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ec2f0492da8a
Implement SWGL fast-path for box shadows. r=jrmuizel

Comment 11

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/ec2f0492da8a

Comment 12

[Alexandru Ionescu (needinfo me) [:alexandrui]]

== Change summary for alert #30123 (as of Wed, 19 May 2021 03:25:26 GMT) ==

Improvements:

Ratio	Suite	Test	Platform	Options	Absolute values (old vs new)
2%	tresize (docs)		linux1804-64-shippable-qr	e10s stylo webrender-sw	20.62 -> 20.14

For up to date results, see: https://treeherder.mozilla.org/perfherder/alerts?id=30123