All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=773704

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=5d8f36c5092c5c787a915faa4063259d5fb963d8e1382e5505ff99c11ac7738e


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

android-nexus6

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8966017655968973744

=== BISECT JOB RESULTS ===
NO Perf regression found

Bisect Details
  Configuration: android_nexus6_perf_bisect
  Benchmark    : system_health.common_mobile
  Metric       : cpu_time_percentage_avg/load_chrome/load_chrome_blank

Revision             Result                      N
chromium@506531      0.117793 +- 0.00816834      21      good
chromium@506628      0.118182 +- 0.00735043      21      bad

To Run This Test
  src/tools/perf/run_benchmark -v --browser=android-chromium --output-format=chartjson --upload-results --pageset-repeat=1 --also-run-disabled-tests --story-filter=load.chrome.blank system_health.common_mobile

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8966017655968973744


For feedback, file a bug with component Speed>Bisection

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8964635107576963120

Tried a different range.

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

Hi mlippautz@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 : Michael Lippautz
  Commit : f46a92c2a8c716c6ad49ea61c4283bdffba3e52a
  Date   : Wed Oct 04 11:24:09 2017
  Subject: [heap] MC: Parallel marking for the atomic pause

Bisect Details
  Configuration: android_nexus6_perf_bisect
  Benchmark    : system_health.common_mobile
  Metric       : cpu_time_percentage_avg/load_chrome/load_chrome_blank
  Change       : 3.28% | 0.114191548134 -> 0.117933583626

Revision                           Result                      N
chromium@506414                    0.114192 +- 0.00193313      6       good
chromium@506422                    0.113655 +- 0.00355562      6       good
chromium@506424                    0.113134 +- 0.00327495      6       good
chromium@506425                    0.114107 +- 0.00532699      9       good
chromium@506425,v8@f46a92c2a8      0.116576 +- 0.00423149      14      bad       <--
chromium@506425,v8@22069a18b9      0.117594 +- 0.00501626      9       bad
chromium@506426                    0.117173 +- 0.00482187      9       bad
chromium@506429                    0.117841 +- 0.00236016      6       bad
chromium@506444                    0.117654 +- 0.00650017      9       bad
chromium@506473                    0.117646 +- 0.00325128      6       bad
chromium@506531                    0.117934 +- 0.00431756      6       bad

To Run This Test
  src/tools/perf/run_benchmark -v --browser=android-chromium --output-format=chartjson --upload-results --pageset-repeat=1 --also-run-disabled-tests --story-filter=load.chrome.blank system_health.common_mobile

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8964635107576963120


For feedback, file a bug with component Speed>Bisection

Thanks!

This is expected as we make use of more parallelism during the main garbage collection phase. Since the main thread is blocked on this work, we need to race to finish as fast as possible.

 Issue 773691  has been merged into this issue.