1416073 - 19% of WebRenderLayerManager::EndTransaction during MotionMark is in nsHTMLScrollFrame::ComputeScrollMetaData

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, enhancement, P1)

Description

[Jeff Muizelaar [:jrmuizel]]

It seems like we do this work once per moving rectangle. Perhaps we can just do it once?

Comment 1

[Kartikaya Gupta (email:[e-mail])]

I assume this is happening because of the call site at [1] rather than from ScrollingLayersHelper. Should be easy to fix with a temp cache.

[1] https://searchfox.org/mozilla-central/rev/30ead7d1ae5bf95b8bc0fd67b950cd46ca05e32c/gfx/layers/wr/WebRenderScrollData.cpp#88

Comment 2

[Kartikaya Gupta (email:[e-mail])]

I wrote a patch. Uncompiled locally but here's a try push: https://treeherder.mozilla.org/#/jobs?repo=try&revision=ba76bc23debcf282e9ede8aa0415eab0cef0a7bb

This should reduce it significantly. If the ViewIDForASR call still shows up a significant cost in the profile (a la bug 1412112) I can add an std::unordered_map<ActiveScrolledRoot*,FrameMetrics::ViewID> somewhere to speed it up, and reuse that cache across both WebRenderScrollData stuff and ScrollingLayerHelper per-transaction. I can do it in bug 1412112 if you think it'll help.

Comment 3

[Kartikaya Gupta (email:[e-mail])]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=78d60b7a3f309c510aba7167c847e24d76d573db might be better. Will check in the morning.

Comment 4

[Kartikaya Gupta (email:[e-mail])]

Attachment: Bug 1416073 - Avoid calling the expensive ComputeScrollMetadata function if we already computed that metadata before.

Review commit: https://reviewboard.mozilla.org/r/198604/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/198604/

Comment 5

[Jeff Muizelaar [:jrmuizel]]

Comment on attachment 8927289 [details]
Bug 1416073 - Avoid calling the expensive ComputeScrollMetadata function if we already computed that metadata before.

https://reviewboard.mozilla.org/r/198604/#review204356

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/dc46db3919a0
Avoid calling the expensive ComputeScrollMetadata function if we already computed that metadata before. r=jrmuizel

Comment 7

[Noemi Erli[:noemi_erli]]

https://hg.mozilla.org/mozilla-central/rev/dc46db3919a0