The log itself ( "cras_client: server_fd_state: wait_for_socket" ) is useful, but we need to find a way to avoid logging Chrome's argument.

+vapier
Hi vapier, not sure if you are familiar with the implementation and config of syslog but any suggestion is appreciated. Thanks!

The cmdline arguments of chrome (the same as /proc/[pid]/cmdline) are prepended to syslog messages.

At first I thought this was the cmdline annotation provided in imuxsock module
( http://www.rsyslog.com/doc/v8-stable/configuration/modules/imuxsock.html )

But I found that SystemLogSocketAnnotate is off by default. Also, enabling it in /etc/rsyslog.chromeos resulted in extra annotations.
So it seems unrelated.

Then I checked other configs in /etc/rsyslog.chromeos ( https://cs.corp.google.com/chromeos_public/src/platform2/init/rsyslog.chromeos?q=rsyslog.chromeos+package:%5Echromeos_public$&dr ) but did not found any config specific to chrome.

Then I checked how chrome open syslog( https://cs.chromium.org/chromium/src/base/syslog_logging.cc?q=syslog&dr=C&l=84 ),  but failed to find anything suspected either. The syslog from cras_client did not go through that path.

The recent uprev of rsyslog from 5 to 8  ( https://bugs.chromium.org/p/chromium/issues/detail?id=668607 ) is not related either because this issue happens before the uprev.

Then I took a peach-pit install R40 image on it because I roughly remember there was no such log long time ago.
Then I found that there was no chrome log on R40.

So, I will bisect and see how did the behavior changed if there is no more clue.

it isn't being prepended to all logs, it's only being prepended to cras logs.  it's supposed to be automatic based on the pid ... i'm not sure why the pid is being reported as chrome when it should be reported as cras.  cras doesn't use libbase, so i wouldn't look at that src/base/ code.  it does all its own syslog() calls.

maybe cras should be calling openlog() with LOG_PID ?

Chrome uses libcras so the process is chrome.
I think this CL is related https://chromium-review.googlesource.com/#/c/261601/
I will check it. Thanks for the help!

I got it!
https://chromium-review.googlesource.com/#/c/261601/ removes openlog in libcras so to leave syslog alone from whoever uses libcras. In that CL, we removed non-critical logs so libcras does not write too many logs.
In https://chromium-review.googlesource.com/359938, we added some DEBUG level log.
Now I should remove those debug log and only log when error happens.

Thanks!

Uploaded https://chromium-review.googlesource.com/461699 to remove non-critical logs and only logs when important function fails.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/third_party/adhd/+/f614b5c71ee7ddb286c1c776289b4953a3e775da

commit f614b5c71ee7ddb286c1c776289b4953a3e775da
Author: Cheng-Yi Chiang <cychiang@chromium.org>
Date: Thu Apr 06 10:29:38 2017

CRAS: remove non-critical logs in libcras and cras_util

Remove non-critial logs in libcras and cras_utils.
Only logs when important call fails.
Fix the return code checking in cras_set_thread_priority.

BUG= chromium:705124 
TEST=check there is no redundant logs about server_fd_state.
TEST=check there is message warning that schedparam call fails on board
that does not allow realtime priority (because rt-limit is not set yet)

Change-Id: I4a182001fb661e42bcbc22104b354fc01a81eaa5
Reviewed-on: https://chromium-review.googlesource.com/461699
Commit-Ready: Cheng-Yi Chiang <cychiang@chromium.org>
Tested-by: Cheng-Yi Chiang <cychiang@chromium.org>
Reviewed-by: Dylan Reid <dgreid@chromium.org>

[modify] https://crrev.com/f614b5c71ee7ddb286c1c776289b4953a3e775da/cras/src/common/cras_util.c
[modify] https://crrev.com/f614b5c71ee7ddb286c1c776289b4953a3e775da/cras/src/libcras/cras_client.c

Verified in Chrome OS 9801.0.0, 62.0.3174.0.