1457466 - Use async scene building better (i.e. make scrolling smooth on pages with slow scene builds)

Status: RESOLVED FIXED

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

Description

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

We've turned on the scene builder thread with gfx.webrender.async-scene-build, but since *all* the transactions are going through that thread, including the GenerateFrame transactions with APZ transforms, APZ scrolling is still slow on pages with slow scene builds. http://tests.themasta.com/gibberish.txt is a good example page.

We need to make the GenerateFrame transaction not go through the scene builder thread so that it can race ahead and generate frames even while the scene builder is stuck on a slow scene build.

Comment 1

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

Attachment: WIP

This is basically all that's needed. However, the OMTA transforms are also baked into the GenerateFrame transactions, which means we need to fix bug 1453360 before we do this, so that we don't try to generate frames with incomplete animation info.

Comment 2

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

Attachment: Bug 1457466 - Trigger a render/composite after an async scene build has been swapped in.

Review commit: https://reviewboard.mozilla.org/r/241748/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/241748/

Comment 3

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

Attachment: Bug 1457466 - Make the GenerateFrame transaction bypass the scene builder thread.

This allows frames to be generated by the render backend thread even
while the scene builder thread is busy with a long scene build. The
GenerateFrame transaction also contains APZ and OMTA information, so
this allows the user to scroll and view OMTAnimations during long scene
builds.

Review commit: https://reviewboard.mozilla.org/r/241750/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/241750/

Comment 5

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

Comment on attachment 8973280 [details]
Bug 1457466 - Trigger a render/composite after an async scene build has been swapped in.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/241748/diff/1-2/

Comment 6

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

Comment on attachment 8973281 [details]
Bug 1457466 - Make the GenerateFrame transaction bypass the scene builder thread.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/241750/diff/1-2/

Comment 7

[Nicolas Silva [:nical]]

Comment on attachment 8973281 [details]
Bug 1457466 - Make the GenerateFrame transaction bypass the scene builder thread.

https://reviewboard.mozilla.org/r/241750/#review249212

Comment 8

[Nicolas Silva [:nical]]

Comment on attachment 8973280 [details]
Bug 1457466 - Trigger a render/composite after an async scene build has been swapped in.

https://reviewboard.mozilla.org/r/241748/#review249218

Comment 9

[Mozilla Autoland]

We're sorry, Autoland could not rebase your commits for you automatically. Please manually rebase your commits and try again.

hg error in cmd: hg rebase -s cbdb39dccbc09e36f3f89de7d74da3c9203fa08e -d ba91fec47e90: rebasing 463171:cbdb39dccbc0 "Bug 1457466 - Trigger a render/composite after an async scene build has been swapped in. r=nical"
merging gfx/layers/ipc/CompositorBridgeParent.cpp
merging gfx/webrender_bindings/src/bindings.rs
merging gfx/webrender_bindings/webrender_ffi_generated.h
rebasing 463172:2f3134391707 "Bug 1457466 - Make the GenerateFrame transaction bypass the scene builder thread. r=nical" (tip)
merging gfx/webrender_bindings/WebRenderAPI.cpp
merging gfx/webrender_bindings/WebRenderAPI.h
warning: conflicts while merging gfx/webrender_bindings/WebRenderAPI.cpp! (edit, then use 'hg resolve --mark')
unresolved conflicts (see hg resolve, then hg rebase --continue)

Comment 10

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

Comment on attachment 8973280 [details]
Bug 1457466 - Trigger a render/composite after an async scene build has been swapped in.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/241748/diff/2-3/

Comment 11

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

Comment on attachment 8973281 [details]
Bug 1457466 - Make the GenerateFrame transaction bypass the scene builder thread.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/241750/diff/2-3/

Comment 12

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/31d09eea3629
Trigger a render/composite after an async scene build has been swapped in. r=nical
https://hg.mozilla.org/integration/autoland/rev/8c90bee8f6f3
Make the GenerateFrame transaction bypass the scene builder thread. r=nical

Comment 13

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

https://hg.mozilla.org/mozilla-central/rev/31d09eea3629
https://hg.mozilla.org/mozilla-central/rev/8c90bee8f6f3