1222944 - [mozrunner] Dump kernel log for B2G emulator

Status: RESOLVED WONTFIX

(Testing :: Mozbase, defect, P3)

Description

[Edgar Chen [:edgar]]

Kernel log is helpful when debugging some test failure which is caused by emulator environment, like Bug 1202310 comment 4. It will be very handy if we could dump it when running emulator tests.

Comment 1

[Edgar Chen [:edgar]]

I already have a WIP patch, will attach it later.

Comment 2

[Edgar Chen [:edgar]]

Attachment: WIP, Patch, v1

Comment 3

[Edgar Chen [:edgar]]

Attachment: WIP, Patch, v2

Comment 4

[Edgar Chen [:edgar]]

Attachment: MozReview Request: Bug 1222944 - [mozrunner] Dump kernel log for B2G emulator

Review commit: https://reviewboard.mozilla.org/r/28113/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/28113/

Comment 5

[Edgar Chen [:edgar]]

Try result: https://treeherder.mozilla.org/#/jobs?repo=try&revision=91647ac6cb35&group_state=expanded

Comment 6

[Edgar Chen [:edgar]]

Comment on attachment 8698780 [details]
MozReview Request: Bug 1222944 - [mozrunner] Dump kernel log for B2G emulator

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/28113/diff/1-2/

Comment 7

[Andrew Halberstadt [:ahal]]

Comment on attachment 8698780 [details]
MozReview Request: Bug 1222944 - [mozrunner] Dump kernel log for B2G emulator

https://reviewboard.mozilla.org/r/28113/#review25309

This looks great! Just one issue below.

::: testing/mozbase/mozrunner/mozrunner/devices/base.py:148
(Diff revision 1)
> +            #save kernel log

nit: space after #

::: testing/mozbase/mozrunner/mozrunner/devices/base.py:152
(Diff revision 1)
> +            kmsg_args = [self.app_ctx.adb, '-s', '%s' % serial,
> +                         'shell', 'cat', '/proc/kmsg']

'cat' will just return right away and miss all the following output from the actual job. I think you want to use 'tail -f /proc/kmsg' instead. If you want the full file dumped from the very beginning you can use 'tail -f -n +0 /proc/kmsg' (assuming the tail binary on the emulator exists and is the same as the one on my linux machine).

Comment 8

[Andrew Halberstadt [:ahal]]

https://reviewboard.mozilla.org/r/28113/#review25309

> 'cat' will just return right away and miss all the following output from the actual job. I think you want to use 'tail -f /proc/kmsg' instead. If you want the full file dumped from the very beginning you can use 'tail -f -n +0 /proc/kmsg' (assuming the tail binary on the emulator exists and is the same as the one on my linux machine).

Just tested, 'tail' doesn't exist by default, but comes with busybox.. So I guess we either need to come up with an equivalent to 'tail -f' or add a check to only save the kernel log if busybox is installed.

Comment 9

[Edgar Chen [:edgar]]

(In reply to Andrew Halberstadt [:ahal] from comment #8)
> https://reviewboard.mozilla.org/r/28113/#review25309
> 
> > 'cat' will just return right away and miss all the following output from the actual job. I think you want to use 'tail -f /proc/kmsg' instead. If you want the full file dumped from the very beginning you can use 'tail -f -n +0 /proc/kmsg' (assuming the tail binary on the emulator exists and is the same as the one on my linux machine).
> 
> Just tested, 'tail' doesn't exist by default, but comes with busybox.. So I
> guess we either need to come up with an equivalent to 'tail -f' or add a
> check to only save the kernel log if busybox is installed.

Thanks for your comment, will address this in next version.

Comment 10

[Edgar Chen [:edgar]]

No longer work on this.

Comment 11

[Hsin-Yi Tsai (she/her) [:hsinyi]]

I don't think we are going to move this on due to the latest B2G announcement.