All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=830829

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=8115cd981a4233de622d5d104006b662479f304fd8c8551e6606ed549667956f


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

chromium-rel-win8-dual

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/149837dcc40000

📍 Couldn't reproduce a difference.
https://pinpoint-dot-chromeperf.appspot.com/job/149837dcc40000

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/17bea634c40000

📍 Found a significant difference after 1 commit.
https://pinpoint-dot-chromeperf.appspot.com/job/17bea634c40000

Adding fieldtrial config for the IncompatibleApplicationsWarning feature by pmonette@chromium.org
https://chromium.googlesource.com/chromium/src/+/7a86e22e588d7941bde54bdb4a8c58c23e502836

Understanding performance regressions:
  http://g.co/ChromePerformanceRegressions

+johnchen@chromium.org, benchmark owner

Hi John,

The CL I landed to enable the ModuleDatabase feature causes an increased CPU load in your benchmark. This is completely expected from the feature, as it adds a bunch of expansive background tasks.

But in theory, because the tasks are marked as background, the scheduler should only schedule them when there are idle CPU cycles available.

Is there a way to confirm that the feature doesn't impact this benchmark in any other way than the extra CPU time? I'm talking about speed and memory related metrics.

I'd like to get this bug close as "Working as intended" if that's the case. Thanks!

Since the increased CPU load is expected, I think closing the bug as "working as intended" is the right step. We have perf benchmarks that also measure memory and other metrics. If you don't receive any bugs about regressions in those areas, then it should be safe to assume that there are no other measurable impacts. If you like, you can use the perf dashboard (https://chromeperf.appspot.com/report) to check if there are any regressions around your CL.

Thanks. I haven't seen anything else than increase CPU time, so I'll close this bug.

I will still continue to monitor the performance of this feature.