All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=629326

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgyu7wtgsM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgqqCKoQoM


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

chromium-rel-mac-retina

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/9006756272981201200

=== Auto-CCing suspected CL author ericrk@chromium.org ===

Hi ericrk@chromium.org, the bisect results pointed to your CL below as possibly
causing a regression. Please have a look at this info and see whether
your CL be related.


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


===== SUSPECTED CL(s) =====
Subject : Disable GPU raster for OSX 10.9
Author  : ericrk
Commit description:
  
 crbug.com/611310  contains a report of a rendering issue on 10.9. As I
haven't been able to repro locally, I was hoping to get more data on
this issue during beta/canary, but no additional reports have come in.
In order to allow us to launch to stable with lower risk, this CL
disables GPU raster on 10.9, which only accounts for ~7% of mac users.

We may re-enable this for M53 Beta M54 Canary in order to track down the
issue in question, and hopefully launch to 10.9 in M53.

BUG= 611310 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2151393002
Cr-Commit-Position: refs/heads/master@{#405902}
Commit  : 51630e3efbcde407cdc7c4e0f35cba88a2090601
Date    : Fri Jul 15 23:44:23 2016


===== TESTED REVISIONS =====
Revision         Mean     Std Dev  N  Good?
chromium@405900  4559385  247113   5  good
chromium@405901  4399930  306254   5  good
chromium@405902  5130263  349130   5  bad    <--
chromium@405903  5177836  361837   5  bad
chromium@405905  5089449  316210   5  bad
chromium@405909  5362940  104344   5  bad
chromium@405918  5241065  319759   5  bad

Bisect job ran on: mac_retina_perf_bisect
Bug ID: 629326

Test Command: src/tools/perf/run_benchmark -v --browser=release --output-format=chartjson --upload-results --also-run-disabled-tests tracing.tracing_with_debug_overhead
Test Metric: Max event size in bytes per second/Max event size in bytes per second
Relative Change: 14.95%
Score: 95.0

Buildbot stdio: http://build.chromium.org/p/tryserver.chromium.perf/builders/mac_retina_perf_bisect/builds/1428
Job details: https://chromeperf.appspot.com/buildbucket_job_status/9006756272981201200


Not what you expected? We'll investigate and get back to you!
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5818833323950080

| O O | Visit http://www.chromium.org/developers/speed-infra/perf-bug-faq
|  X  | for more information addressing perf regression bugs. For feedback,
| / \ | file a bug with component Tests>AutoBisect.  Thank you!

This is somewhat expected - we disabled GPU rasterization on 10.9 due to correctness concerns. We may re-enable in the future after more debugging.

Mac OS 10.9 accounts for ~7% of users, and we already have a dedicated mac 10.9 bot - it might make sense to upgrade the Mac retina bot to >10.9, as it's not representing the typical mac retina user at this point.

That seems to be the cause of the tracing regressions, but there were some filters regressions mixed in there too that shot way up above previous levels. I've split those off into  issue 632342  since I think they're unrelated to GPU raster.