The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/93c0968c8188befdaeaf1d49a98ad9086fa4a0f3

commit 93c0968c8188befdaeaf1d49a98ad9086fa4a0f3
Author: sabbakumov <sabbakumov@yandex-team.ru>
Date: Thu May 04 05:10:29 2017

Use another file and field for wakeups count

On some Linux systems (like Ubuntu 14.04.5 or Ubuntu 16.04) with
4.8.0-49-generic kernel there's no /proc/<pid>/sched file. Or it exists
but doesn't have the required se.statistics.nr_wakeups field.
This causes TaskManagerBrowserTest.IdleWakeups test to fail and in
Chrome Task Manager all the Idle Wakeups counts are 0.

After some research I found out that the voluntary_ctxt_switches field
in file /proc/<pid>/status is practically the same as the previous
one. Using that field helps the test to pass.

BUG= 717863 

Review-Url: https://codereview.chromium.org/2859763002
Cr-Commit-Position: refs/heads/master@{#469270}

[modify] https://crrev.com/93c0968c8188befdaeaf1d49a98ad9086fa4a0f3/base/process/process_metrics_linux.cc

sabbakumov@ Could you please help us with the steps to verify this issue from TE-End.

Thank You...

kkaluri@ Sure.
1. Install Ubuntu 16.04 with the 4.8.0-49-generic kernel.
2. Open Chrome (before 93c0968c8188befdaeaf1d49a98ad9086fa4a0f3 commit, since I fixed the issue after that commit).
3. Open Chrome Task Manager.
4. Right click - select Idle Wakeups
5. Note that all wakeups count are 0.

Also run the following command from the terminal:
file /proc/1/sched

The output of the command is:
/proc/1/sched: cannot open `/proc/1/sched' (No such file or directory)

That means the file Chrome uses for wakeups count is not available.

Thank you for providing more feedback. Adding requester "kkaluri@chromium.org" to the cc list and removing "Needs-Feedback" label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Unable to reproduce the issue on Ubuntu 16.04 using chrome reported version #60.0.3088.0 .

Attached a screen shot for reference.

Following are the steps followed to reproduce the issue.
------------
1. Opened chrome.
2. Opened Chrome Task Manager.
3. Right clicked and selected Idle Wakeups.
4. Observed that idle wakeups were non-zero.

sabbakumov@ - Could you please check the screenshot and please let us know if anything missed from our side.

Thanks...!!

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	Screenshot from 2017-06-07 15-57-58.png 533 KB View Download

Do you use Chrome before my patch listed above?
Also, what's your kernel version?

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	Screenshot.png 628 KB View Download

Thank you for providing more feedback. Adding requester "krajshree@chromium.org" to the cc list and removing "Needs-Feedback" label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

As per comment #7 tested in chrome Stable# 59.0.3071.115(Revision - 464641)before fix build with 4.4.0-79-generic on Ubuntu 14.04 & 16.04 and not able to reproduce the issue.Please find the screen shots for your reference.

@Reporter:Could you please let me know if i have missed anything and if possible,Please create new profile without extensions and apps.Re-check once and let us know the observations of the issue which would help us to triage the issue further.

Thanks in Advance.

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@ sabbakumov : Could you please update on comment #9.Which would help us to triage the issue further.

Thanks in Advance.

Could you please double check that you use 4.8.0-52-generic Linux kernel? Also instead of "file" command try to use:
cat /proc/1/sched | grep se.statistics.nr_wakeups

Just like in the Comment 7.

Thank you for providing more feedback. Adding requester "rbasuvula@chromium.org" to the cc list and removing "Needs-Feedback" label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Also please double check that you use Chrome before my patch listed above.

Tested the issue on Linux Ubuntu 14.04 4.4.0-75-generic kernel using chrome version 60.0.3112.66 with the below steps

1. Opened chrome.
2. Opened Chrome Task Manager.
3. Right clicked and selected Idle Wakeups.
4. Observed that idle wakeups as like screenshot attached.
5. executed the command cat /proc/1/sched | grep se.statistics.nr_wakeups in terminal

Please find the attached screen shot and confirm if anything missed here.
attached screen shot of the issue on chrome version 60.0.3088.0  as well.
Also please confirm is this issue specific to 4.8.0-52-generic Linux kernel?

Thanks,

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	717863(60.0.3088.0).png 383 KB View Download

Deleted: 717863.png 421 KB

	717863.png 421 KB View Download

It seems that all is right.
Probably the issue is specific to the kernel settings.

Thank you for providing more feedback. Adding requester "kavvaru@chromium.org" to the cc list and removing "Needs-Feedback" label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Thanks for the update! Some one from "Task Manager" dev team please look in to this issue.

Thank You!

Adding TE-NeedsTriageFromMTV as the issue seems specific to 4.8.0-52-generic Linux kernel.

MTV@ Could some one from MTV please check this issue if you have specific kernel.

Thanks,

Issue has not been modified or commented on in the last 365 days, please re-open or file a new bug if this is still an issue.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot