All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=753991

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=0325f8258e3ebe1beed3fd2b24f28f27e0cd321142c2fb562c6b4912707bdaf5


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

chromium-rel-mac11-air

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8971703049050731040

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

Bisect Details
  Configuration: mac_air_perf_bisect
  Benchmark    : tracing.tracing_with_debug_overhead
  Metric       : peak_event_rate_avg/peak_event_rate_avg

Revision             Result                  N
chromium@491932      28557.8 +- 3551.91      20      good
chromium@491975      28863.4 +- 3852.05      21      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 tracing.tracing_with_debug_overhead

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8971703049050731040


For feedback, file a bug with component Speed>Bisection

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8971644487261040208

+simonhatch, hmm this also looks a pretty sharp jump. 
Is there any known bisect outage these days? I'm getting a bunch of bisects like this failing

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8971638137724393712

I just poked through the graphs, and it looks like we're having problems because the average is monitored. There are big jumps in wikipedia and amazon at the revision range immediately prior, but somehow when you smush together all the charts the average looks like a jump shifted to the next revision range. I kicked off a bisect on amazon and fixed the alerting to be per-page.

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

Suspected Commit
  Author : xunjieli
  Commit : 357e1deefca78c61e457f340270c9cd6f38321f5
  Date   : Thu Aug 03 22:16:30 2017
  Subject: [wpr-go] Use a dummy cert if no cert is recorded

Bisect Details
  Configuration: mac_air_perf_bisect
  Benchmark    : tracing.tracing_with_debug_overhead
  Metric       : peak_event_rate_avg/http___www.amazon.com
  Change       : 123.40% | 11290.3333333 -> 25223.0

Revision                                 Result                  N
chromium@491853                          11290.3 +- 1067.23      6      good
chromium@491893                          11658.7 +- 1191.78      6      good
chromium@491913                          11295.0 +- 722.647      6      good
chromium@491923                          11253.0 +- 1402.44      6      good
chromium@491924                          11244.3 +- 896.331      6      good
chromium@491924,catapult@b0f1e24d46      11437.5 +- 1182.25      6      good
chromium@491924,catapult@357e1deefc      25083.2 +- 1471.56      6      bad       <--
chromium@491925                          25865.0 +- 2886.81      6      bad
chromium@491926                          25482.0 +- 3705.78      6      bad
chromium@491928                          24776.8 +- 1920.47      6      bad
chromium@491932                          25223.0 +- 2049.9       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=http...www.amazon.com tracing.tracing_with_debug_overhead

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8971638137724393712


For feedback, file a bug with component Speed>Bisection

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

Bisect Details
  Configuration: mac_air_perf_bisect
  Benchmark    : tracing.tracing_with_debug_overhead
  Metric       : peak_event_rate_avg/peak_event_rate_avg

Revision             Result                  N
chromium@491932      29269.1 +- 5067.89      21      good
chromium@491975      29666.3 +- 6393.57      21      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 tracing.tracing_with_debug_overhead

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8971644487261040208


For feedback, file a bug with component Speed>Bisection