All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=753984

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=4d79e395f556ecad23eb2a43f723841e78d494dca3821247e3cc89b1ba6b015c


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

android-nexus6
chromium-rel-mac11-pro

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8971703331560173872

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

Suspected Commit
  Author : Ulan Degenbaev
  Commit : feb3ee40d03137ffcc2be98a01f6ea936cdf45e1
  Date   : Mon Aug 07 16:21:24 2017
  Subject: [heap] Disable parallel scavenge.

Bisect Details
  Configuration: mac_pro_perf_bisect
  Benchmark    : memory.long_running_idle_gmail_tbmv2
  Metric       : v8-gc-scavenger_max/v8-gc-scavenger_max
  Change       : 199.86% | 4.39 -> 13.164

Revision                           Result                  N
chromium@492413                    4.39 +- 1.33667         6      good
chromium@492437                    5.10517 +- 1.73433      6      good
chromium@492443                    4.474 +- 0.883566       6      good
chromium@492444                    4.2255 +- 0.661932      6      good
chromium@492444,v8@a7a166e30c      4.48083 +- 1.69693      6      good
chromium@492444,v8@ceb55494bd      4.86483 +- 2.06043      6      good
chromium@492444,v8@feb3ee40d0      13.5083 +- 3.40227      6      bad       <--
chromium@492444,v8@864837ff3c      13.2037 +- 1.97775      6      bad
chromium@492445                    14.1668 +- 2.7881       6      bad
chromium@492446                    13.8463 +- 1.83669      6      bad
chromium@492449                    14.7722 +- 4.72785      6      bad
chromium@492460                    13.7248 +- 4.38835      6      bad
chromium@492507                    13.164 +- 2.77249       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 memory.long_running_idle_gmail_tbmv2

More information on addressing performance regressions:
  http://g.co/ChromePerformanceRegressions

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8971703331560173872


For feedback, file a bug with component Speed>Bisection