All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=676771

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgn-LTrwoM


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

chromium-rel-mac-retina

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8992497210171557264

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8992497201210023008

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8982628346951844416

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8982619763360904112

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

Hi ulan@chromium.org, the bisect results pointed to your CL, please take a look at the
results.


=== BISECT JOB RESULTS ===
Perf regression found with culprit

Suspected Commit
  Author : ulan
  Commit : 039e29f7505cf75d27d7681fab51d50f53dcc7bd
  Date   : Mon Dec 19 11:34:34 2016
  Subject: [heap] Use RAIL mode for starting incremental marking.

Bisect Details
  Configuration: mac_retina_perf_bisect
  Benchmark    : v8.browsing_desktop
  Metric       : v8-gc-latency-mark-compactor_max/browse_media/browse_media_pinterest
  Change       : 452.89% | 6.715 -> 37.1268333333

Revision                           Result                  N
chromium@439529                    6.715 +- 4.24589        6       good
chromium@439559                    6.9245 +- 2.54744       6       good
chromium@439567                    6.965 +- 3.62994        6       good
chromium@439571                    6.56593 +- 2.99395      14      good
chromium@439571,v8@81dd9847cf      14.5711 +- 57.2469      14      good
chromium@439571,v8@58247e87be      6.5585 +- 2.26451       6       good
chromium@439571,v8@039e29f750      38.5033 +- 24.1247      14      bad       <--
chromium@439571,v8@52702e55aa      40.4573 +- 16.8782      9       bad
chromium@439571,v8@8ac9e55aa6      37.5659 +- 21.5011      14      bad
chromium@439572                    33.5945 +- 16.5156      6       bad
chromium@439573                    38.6853 +- 8.93025      6       bad
chromium@439574                    43.4402 +- 12.5199      6       bad
chromium@439589                    39.6957 +- 21.1855      6       bad
chromium@439649                    37.1268 +- 14.5484      6       bad

To Run This Test
  src/tools/perf/run_benchmark -v --browser=release --output-format=chartjson --upload-results --pageset-repeat=1 --also-run-disabled-tests --story-filter=browse.media.pinterest v8.browsing_desktop

Debug Info
  https://chromeperf.appspot.com/buildbucket_job_status/8982628346951844416

Is this bisect wrong?
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5277600044285952


| 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 Speed>Bisection.  Thank you!

The regression is GC timing related, will improve with concurrent marking.

Issue 676776 has been merged into this issue.