All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=643720

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg0dTzswoM


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

chromium-rel-mac10

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/9002613703964583200

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

Hi ulan@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 : [heap] Simplify heuristics for incremental step size.
Author  : ulan
Commit description:
  
This patch removes the code for speeding up marking.

Now the step size depends on allocated bytes and
invoked write barriers.

We also ensure that the step size is large enough to
justify the overhead of interrupting the generated code.

BUG= chromium:616434 
LOG=NO

Review-Url: https://codereview.chromium.org/2290333002
Cr-Commit-Position: refs/heads/master@{#39067}
Commit  : 71a793e4b1026e69d4009df0a419fe260fe1a235
Date    : Thu Sep 01 08:32:38 2016


===== TESTED REVISIONS =====
Revision                       Mean      Std Dev     N  Good?
chromium@415906                0.499696  0.0469463   5  good
chromium@415923                0.421279  0.00869185  5  good
chromium@415932                0.484293  0.0402211   5  good
chromium@415933                0.485286  0.0525502   5  good
chromium@415933,v8@432790c92c  0.43023   0.0364413   5  good
chromium@415933,v8@706cbe3840  0.508105  0.0551234   5  good
chromium@415933,v8@71a793e4b1  1.75209   0.134544    5  bad    <--
chromium@415934                1.78072   0.167992    5  bad
chromium@415935                1.72266   0.206492    5  bad
chromium@415937                1.77479   0.31664     5  bad
chromium@415941                1.88301   0.13528     5  bad

Bisect job ran on: mac_10_10_perf_bisect
Bug ID: 643720

Test Command: src/tools/perf/run_benchmark -v --browser=release --output-format=chartjson --upload-results --also-run-disabled-tests memory.long_running_idle_gmail_background_tbmv2
Test Metric: v8-gc-incremental-step_avg/v8-gc-incremental-step_avg
Relative Change: 276.83%
Score: 99.9

Buildbot stdio: http://build.chromium.org/p/tryserver.chromium.perf/builders/mac_10_10_perf_bisect/builds/2344
Job details: https://chromeperf.appspot.com/buildbucket_job_status/9002613703964583200


Not what you expected? We'll investigate and get back to you!
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5821316031053824

| 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!

The patch was reverted last week.