All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=770883

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=c2d5fca0198fedb693e3b93f6ec1a40e14dbb32f1536bf6ca12b1cbd5fece7f1


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

chromium-rel-mac-retina
chromium-rel-mac11
chromium-rel-mac11-pro
chromium-rel-mac12
chromium-rel-mac12-mini-8gb
chromium-rel-win10
chromium-rel-win7-dual
chromium-rel-win7-gpu-ati
chromium-rel-win7-gpu-intel
chromium-rel-win7-gpu-nvidia
chromium-rel-win7-x64-dual
chromium-rel-win8-dual
linux-release

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8966810926635254224

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

Bisect Details
  Configuration: winx64intel_perf_bisect
  Benchmark    : system_health.common_desktop
  Metric       : cpu_time_percentage_avg/browse_tech/browse_tech_discourse_infinite_scroll

Revision             Result                     N
chromium@504762      0.340298 +- 0.0275864      21      good
chromium@504839      0.342888 +- 0.0276815      21      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.tech.discourse.infinite.scroll system_health.common_desktop

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8966810926635254224


For feedback, file a bug with component Speed>Bisection

Both regular and ref builds moved together, so likely some test/infra change. Still the memory increases are huge (> 100MiB in worst cases), so probably worth investigating.

:-/ This bug got merged with regressions in memory and other "common" metrics. There is no memory data in the bisect above.

Will split in two and try to bisect again.

system_health.common_desktop regressions moved other to  issue 774415 

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8965857830326856096

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

Bisect Details
  Configuration: winx64_10_perf_bisect
  Benchmark    : system_health.memory_desktop
  Metric       : memory:chrome:all_processes:reported_by_os:system_memory:native_heap:proportional_resident_size_avg/load_news/load_news_wikipedia

Revision             Result                    N
chromium@504759      149664120 +- 3212059      21      good
chromium@504825      149152334 +- 5507049      21      bad

Please refer to the following doc on diagnosing memory regressions:
  https://chromium.googlesource.com/chromium/src/+/master/docs/memory-infra/memory_benchmarks.md

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=load.news.wikipedia system_health.memory_desktop

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8965857830326856096


For feedback, file a bug with component Speed>Bisection

Neither this nor  issue 774415  were able to reproduce.

On the graphs, both ref and non-ref builds move together. So pretty certain this was a hardware or recipe change.

Affected bots are mac12 and win10.

Ned, Annie, do we know about anything specific that may have happened to those bots during that time?

For the moment lowering Pri as this is most likely not a real regression in Chrome. Still, the regressions are huge, so might be nice to figure out what may have happened.

We recently have GPU driver update, wonder if this is related ( issue 767411 )

WontFix-ing since it looks like there was a GPU driver update and we seem to be out of ideas on this bug which is several months old.