All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=617708

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg3LT0sgoM


Bot(s) for this bug's original alert(s):

chromium-rel-mac-hdd

===== BISECT JOB RESULTS =====
Status: completed


===== SUSPECTED CL(s) =====
Subject : Modify ImageTransportSurfaceOverlayMac to allow pipelining
Author  : ericrk
Commit description:
  
This change allows 1 additional frame of pipelining in
ImageTransportSurfaceOverlayMac by switching from a glFinish based
approach to a glFence based one.

Tested for CA framerate regressions - the following cases starve CA
when used with a simple glFlush. This solution (and the previous
glFinish) appear to successfully prevent CA starvation:

Animometer - bouncing png images:
https://trac.webkit.org/export/HEAD/trunk/PerformanceTests/Animometer/developer.html?test-interval=20&display=progress-bar&controller=adaptive&frame-rate=50&kalman-process-error=1&kalman-measurement-error=4&time-measurement=performance&suite-name=SVGsuite&test-name=SVGbouncingPNGimages&complexity=200
Both glFinish and glFence produce ~50 fps in CA/Chrome.

WebGL Liquid Face:
http://alteredqualia.com/xg/examples/liquid_face.html
For liquid face, note that with the glFinish, CA framerate is slightly
higher than Chrome reported framerate (20 vs 15) - with the new
approach, they match more closely (16 vs 15). This may be a negative,
but is still much better than the starvation which is seen with glFlush (5
vs 15).

Improvements:
Telemetry smoothness.top_25_smooth: This change produces good
improvements in first_gesture_scroll_update_latency,
mean_input_event_latency, and mean_main_thread_scroll_latency,
without any significant regressions. See:
https://drive.google.com/file/d/0B2nwXDxTDpGGU215X2xYTE9Bdnc/view?usp=sharing
Animometer Benchmark: This change produces good improvements in a
number of animometer benchmarks. See:
https://docs.google.com/spreadsheets/d/1qK6LfDVMKydbKfkGEi1DuGoSqY2wPJAjPiAL1CCUW-4/edit?usp=sharing

CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_optional_gpu_tests_rel;tryserver.chromium.mac:mac_optional_gpu_tests_rel;tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2028303002
Cr-Commit-Position: refs/heads/master@{#397738}
Commit  : 54e8e3975826ceb886a7e0d8ec07bb38b1192311
Date    : Fri Jun 03 17:19:46 2016


===== TESTED REVISIONS =====
Revision         Mean    Std Dev  N  Good?
chromium@397714  -1.8    1.78885  5  good
chromium@397731  -1.4    1.67332  5  good
chromium@397736  -3.0    4.76095  4  good
chromium@397737  -2.6    1.34164  5  good
chromium@397738  2845.2  364.801  5  bad    <--
chromium@397740  2885.6  203.806  5  bad
chromium@397748  2905.6  190.017  5  bad
chromium@397782  2924.0  109.018  5  bad

Bisect job ran on: mac_hdd_perf_bisect
Bug ID: 617708

Test Command: src/tools/perf/run_benchmark -v --browser=release --output-format=chartjson --upload-results --also-run-disabled-tests media.tough_video_cases
Test Metric: idle_wakeups_gpu/idle_wakeups_gpu
Relative Change: 163655.56%
Score: 99.9

Buildbot stdio: http://build.chromium.org/p/tryserver.chromium.perf/builders/mac_hdd_perf_bisect/builds/571
Job details: https://chromeperf.appspot.com/buildbucket_job_status/9010579167242625552


Not what you expected? We'll investigate and get back to you!
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5823278183088128

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