All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=608731

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg1OiqugoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICglK2vrwoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICglM2SuAoM


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

android-nexus5
android-nexus5X

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

Hi mlippautz@chromium.org, the bisect results pointed to your CL below as possibly
causing a regression. Please have a look at this info and see whether
your CL be related.


===== BISECT JOB RESULTS =====
Status: completed


===== SUSPECTED CL(s) =====
Subject : Reland of "[heap] Uncommit pooled pages concurrently"
Author  : mlippautz
Commit description:
  
- Move the concurrent unmapping to MemoryAllocator
- Hide (private) members where possible
- MemoryAllocator:Free is now the bottleneck for freeing
- Pooled pages are either allocated from a set of pooled pages are obtained
  through work stealing from the concurrent unmapper

BUG= chromium:605866 , chromium:581412
LOG=N

This reverts commit 25ff296c4c8d35c63255531a86f877f20eeaeb62.

Review-Url: https://codereview.chromium.org/1929503002
Cr-Commit-Position: refs/heads/master@{#35910}
Commit  : 45f52fcb60f75bfe5dc5f6a83317a14db631cf18
Date    : Fri Apr 29 14:28:18 2016


===== TESTED REVISIONS =====
Revision                       Mean     Std Dev      N  Good?
chromium@390678                2.70664  0.0218797    5  good
chromium@390694                2.70662  0.0231935    5  good
chromium@390698                2.71676  0.0277799    5  good
chromium@390700                2.69658  0.000843133  5  good
chromium@390700,v8@45f52fcb60  2.99579  0.000105855  5  bad    <--
chromium@390700,v8@b83edcc8b1  2.99599  0.000815294  5  bad
chromium@390701                2.9964   0.00117477   5  bad
chromium@390702                2.99607  0.000506558  5  bad
chromium@390710                3.05606  0.108654     5  bad

Bisect job ran on: android_nexus5X_perf_bisect
Bug ID: 608731

Test Command: src/tools/perf/run_benchmark -v --browser=android-chromium --output-format=chartjson --upload-results --also-run-disabled-tests thread_times.key_idle_power_cases
Test Metric: tasks_per_second_total_all/css-animation.html
Relative Change: 12.91%
Score: 99.9

Buildbot stdio: http://build.chromium.org/p/tryserver.chromium.perf/builders/android_nexus5X_perf_bisect/builds/128
Job details: https://chromeperf.appspot.com/buildbucket_job_status/9013674242031357712


Not what you expected? We'll investigate and get back to you!
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5833466231390208

| O O | Visit http://www.chromium.org/developers/speed-infra/perf-bug-faq
|  X  | for more information addressing perf regression bugs. For feedback,
| / \ | file a bug with component Tests>AutoBisect.  Thank you!

based on bisect results in C#2, mlippautz@ could you please check the issue and update.

Regression is expected. 

The description says that the pages are idle, but the only way we spawn new tasks is through the GC, meaning that the pages actually allocate memory. We decided to keep the concurrent tasks for unmapping because they help latency cases.