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Issue 599910 link

Starred by 2 users
Status: Fixed
Owner:
tdres...@chromium.org
Closed: May 2017
Cc:
█ ymalik@chromium.org
dtapu...@chromium.org
skobes@chromium.org
Components:
EstimatedDays: ----
NextAction: ----
OS: ----
Pri: 2
Type: Bug



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LatencyInfo for events causing smooth scroll is broken

Project Member Reported by tdres...@chromium.org, Apr 1 2016 
What's the latency of an event which triggers a smooth scroll?

Ideally we'd have a value which is roughly comparable with the latency for an event which triggers a non-smooth scroll.

Maybe we should just look at latency until the first frame of the smooth scroll?

Do we have a performance metric looking at smooth scroll FPS?

Comment 1 by dtapu...@chromium.org, Apr 7 2016

Owner: ymalik@chromium.org
Status: Assigned (was: Untriaged)
Yash; is this something that you can think about a solution for?

Currently the gpu frames aren't reported on the trace so that causes some tools not to calculate the latency correctly. I don't think the tools run with smooth scroll on but I don't know if these metrics are used for RAIL score calculation.

Comment 2 by ymalik@chromium.org, Nov 17 2016

Owner: skobes@chromium.org

Comment 3 by tdres...@chromium.org, Jan 19 2017

Labels: -Pri-3 Pri-2
This is causing us to miss a fair bit of latency information.

Bumping up to P2.

Comment 4 by tdres...@chromium.org, May 2 2017

Owner: tdres...@chromium.org
Status: Started (was: Assigned)
I'm taking a look at this. We just need to actually start animating in the same frame as we receive the input, which will have the handy side effect of removing a frame of latency.
Project Member

Comment 5 by bugdroid1@chromium.org, May 17 2017 

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7fe8085f9f4f10d88ec704588adea49392303fbe

commit 7fe8085f9f4f10d88ec704588adea49392303fbe
Author: tdresser <tdresser@chromium.org>
Date: Wed May 17 19:57:51 2017

Reduce composited smooth scroll latency by a frame (also fixes latency UMAs).

Previously input which triggered a smooth scroll didn't scroll
at all on the first frame of the smooth scroll animation.

This introduced unnecessary latency, and also prevented out input
latency instrumentation from realizing that the input produced a
frame.

This removes that latency by starting the animation one frame in,
and causes our input latency pipeline to recognize that this input
triggered a frame being drawn.

The main thread case still needs to be fixed.

BUG= 599910 ,  717652 
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2863103002
Cr-Commit-Position: refs/heads/master@{#472542}

[modify] https://crrev.com/7fe8085f9f4f10d88ec704588adea49392303fbe/cc/animation/animation_host.cc
[modify] https://crrev.com/7fe8085f9f4f10d88ec704588adea49392303fbe/cc/animation/animation_host.h
[modify] https://crrev.com/7fe8085f9f4f10d88ec704588adea49392303fbe/cc/animation/animation_host_unittest.cc
[modify] https://crrev.com/7fe8085f9f4f10d88ec704588adea49392303fbe/cc/animation/scroll_offset_animations_impl.cc
[modify] https://crrev.com/7fe8085f9f4f10d88ec704588adea49392303fbe/cc/animation/scroll_offset_animations_impl.h
[modify] https://crrev.com/7fe8085f9f4f10d88ec704588adea49392303fbe/cc/trees/layer_tree_host_impl.cc
[modify] https://crrev.com/7fe8085f9f4f10d88ec704588adea49392303fbe/cc/trees/layer_tree_host_impl_unittest.cc
[modify] https://crrev.com/7fe8085f9f4f10d88ec704588adea49392303fbe/cc/trees/layer_tree_host_unittest_animation.cc
[modify] https://crrev.com/7fe8085f9f4f10d88ec704588adea49392303fbe/cc/trees/mutator_host.h
[add] https://crrev.com/7fe8085f9f4f10d88ec704588adea49392303fbe/content/browser/renderer_host/input/scroll_latency_browsertest.cc
[modify] https://crrev.com/7fe8085f9f4f10d88ec704588adea49392303fbe/content/test/BUILD.gn

Comment 6 by tdres...@chromium.org, May 29 2017

Status: Fixed (was: Started)
►

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