Add an 'Idle Wake Ups' metric to the Linux task manager, implement backend.

Add an 'Idle Wake Ups' metric to the Linux task manager, implement backend.

BUG=120488
Committed: https://crrev.com/75844fdb8b70aa957fc8bc6bba019c2026fde28f
Cr-Commit-Position: refs/heads/master@{#293991}

[Lei Zhang, 2014-09-06 09:47:56]

thestig@chromium.org changed reviewers:
+ thakis@chromium.org

[Lei Zhang, 2014-09-06 09:47:57]

Applied on top of https://codereview.chromium.org/549753002/

[Nico, 2014-09-07 00:10:58]

nice! lgtm

https://codereview.chromium.org/546193002/diff/1/base/process/process_metrics...
File base/process/process_metrics_linux.cc (right):

https://codereview.chromium.org/546193002/diff/1/base/process/process_metrics...
base/process/process_metrics_linux.cc:87: // Synchronously reading files in
/proc is safe.
"safe" isn't why we have this, it's about speed. I'd say "/proc is in memory, so
reading from it doesn't need to hit the disk." instead.

https://codereview.chromium.org/546193002/diff/1/base/process/process_metrics...
base/process/process_metrics_linux.cc:99: TrimWhitespaceASCII(pairs[i].second,
TRIM_ALL, &value_str);
This looks pretty similar to line 72 of
https://codereview.chromium.org/549753002/diff/40001/base/process/process_met...
– maybe there should be a helper that does the Trimming on first and second

[Lei Zhang, 2014-09-09 06:13:14]

https://codereview.chromium.org/546193002/diff/1/base/process/process_metrics...
File base/process/process_metrics_linux.cc (right):

https://codereview.chromium.org/546193002/diff/1/base/process/process_metrics...
base/process/process_metrics_linux.cc:87: // Synchronously reading files in
/proc is safe.
On 2014/09/07 00:10:57, Nico (hiding) wrote:
> "safe" isn't why we have this, it's about speed. I'd say "/proc is in memory,
so
> reading from it doesn't need to hit the disk." instead.

Filed all over. It's copy+pasted from elsewhere in this file. Maybe I wrote it
in the first place? *shrug*.

https://codereview.chromium.org/546193002/diff/1/base/process/process_metrics...
base/process/process_metrics_linux.cc:99: TrimWhitespaceASCII(pairs[i].second,
TRIM_ALL, &value_str);
On 2014/09/07 00:10:57, Nico (hiding) wrote:
> This looks pretty similar to line 72 of
>
https://codereview.chromium.org/549753002/diff/40001/base/process/process_met...
> – maybe there should be a helper that does the Trimming on first and second

Done.

[Lei Zhang, 2014-09-09 06:14:38]

thestig@chromium.org changed reviewers:
+ phajdan.jr@chromium.org

[Lei Zhang, 2014-09-09 06:14:39]

Pawel: Please review PRESUBMIT.py. base/process/process_metrics_linux.cc reads
from /proc and /sys frequently, so it uses ScopedAllowIO a lot and should be
exempt from the presubmit check.

[Paweł Hajdan Jr., 2014-09-09 12:07:03]

LGTM

[Lei Zhang, 2014-09-09 18:27:07]

The CQ bit was checked by thestig@chromium.org

[commit-bot: I haz the power, 2014-09-09 18:39:28]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/thestig@chromium.org/546193002/80001

[commit-bot: I haz the power, 2014-09-09 19:53:27]

Committed patchset #5 (id:80001) as 1c7d8be730eaadc208592570bac4be3d74542f53

[commit-bot: I haz the power, 2014-09-10 03:55:04]

Patchset 5 (id:??) landed as
https://crrev.com/75844fdb8b70aa957fc8bc6bba019c2026fde28f
Cr-Commit-Position: refs/heads/master@{#293991}