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Issue 707514 link

Starred by 3 users

Issue metadata

Status: WontFix
Owner:
Last visit > 30 days ago
Closed: Sep 10
Cc:
Components:
EstimatedDays: ----
NextAction: ----
OS: ----
Pri: 3
Type: Feature



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Surface synchronization: Consider interaction with cc::Scheduler and layer compositor

Project Member Reported by fsamuel@google.com, Apr 1 2017

Issue description

The layer compositor has a low latency mode and a high latency mode.

In high latency mode, 3 frames can be in flight at a given time (brianderson@, is that correct)?

During resize, that entire pipeline needs to be flushed because layout changes on resize. Thus, a lot of wasted work is happening here.

Can we turn off high latency mode during surface sync?

One thing to investigate is if we can signal to the scheduler that surface IDs are changing rapidly (as a proxy to resize) and so we should switch to low latency mode.


 

Comment 1 by fsamuel@google.com, Apr 1 2017

Cc: vmp...@chromium.org
Define "frames" and "in flight" here, please.
Disclaimer: I don't have a deep understanding of the code yet.

My understanding from brianderson@ in high latency mode, we can be doing main thread work, "compositing" work and raster work for a layout that is likely to change soon. This is wasted work, right?
Labels: -Type-Bug Type-Feature
Status: Available (was: Untriaged)
Set Available/Feature on this type of tracking issue so we don't have to go through them in our triage.

Comment 5 by fsamuel@google.com, Apr 20 2017

Cc: fsam...@chromium.org gklassen@chromium.org
Cc: sunn...@chromium.org
We're planning to add a flush pipeline mode to the scheduler for headless chrome. I haven't flushed out all the details yet but it will probably be a flag on the begin frame args. For cc scheduler it means completing any pending commits and activations (skipping draws) and then waiting until the main thread produces a new commit and activation. Only after that can we draw. ofc the display scheduler also has to run any pending draw callbacks (force activate pending frame?) so that the renderer is unblocked. I think this mode would make a lot of sense for resizing.
Cc: weiliangc@chromium.org
Owner: sunn...@chromium.org
Status: Assigned (was: Available)
Cc: varkha@chromium.org
Blocking: -601863 672962
Components: -Internals>MUS
Project Member

Comment 13 by sheriffbot@chromium.org, Jul 21 2017

Labels: Hotlist-Google
Blocking: -672962
Owner: fsam...@chromium.org
-> fsamuel@ for triage/WontFix
Status: WontFix (was: Assigned)
I'm marking as WontFix for now. This might come up again but for now we're not actively pursuing it.

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