All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=769225

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=ae8a0945219d92a484bb82de2ee3429eaf3e31bf113b5c9029a0e55c8d7a4a96


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

chromium-rel-mac11-air
chromium-rel-mac12
chromium-rel-win7-dual
chromium-rel-win7-x64-dual
chromium-rel-win8-dual
win-high-dpi

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8967310073160167904

=== 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 Degenbaev
  Commit : dc3bbbdbe869262f4a857b8aceadc10b5b12c993
  Date   : Mon Sep 25 04:39:35 2017
  Subject: [heap] Tune the number of concurrent marking tasks.

Bisect Details
  Configuration: winx64_high_dpi_perf_bisect
  Benchmark    : v8.runtimestats.browsing_desktop
  Metric       : v8-gc-incremental-step_sum/browse_search/browse_search_google_india
  Change       : 91.73% | 11.5901666667 -> 22.2215

Revision                           Result                   N
chromium@504002                    11.5902 +- 3.55793       6      good
chromium@504008                    9.4435 +- 0.941563       6      good
chromium@504011                    10.0672 +- 2.92086       6      good
chromium@504012                    11.175 +- 4.24707        6      good
chromium@504012,v8@ff94986d81      10.0933 +- 2.83219       6      good
chromium@504012,v8@dc3bbbdbe8      22.0543 +- 2.31049       6      bad       <--
chromium@504012,v8@8b35cb30de      21.5922 +- 5.23211       6      bad
chromium@504013                    21.9777 +- 2.14827       6      bad
chromium@504022                    22.3352 +- 0.900559      6      bad
chromium@504041                    22.2215 +- 0.892079      6      bad

To Run This Test
  src/tools/perf/run_benchmark -v --browser=release_x64 --output-format=chartjson --upload-results --pageset-repeat=1 --also-run-disabled-tests --story-filter=browse.search.google.india v8.runtimestats.browsing_desktop

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8967310073160167904


For feedback, file a bug with component Speed>Bisection

This reduces improvements from the concurrent marking and is expected.