Re: [RFC PATCH] accouting: account if a task was killed by OOM killer

[Xiaotian Feng <dfeng@redhat.com>]

On 01/14/2010 06:54 AM, Andrew Morton wrote:
> On Mon, 11 Jan 2010 14:40:34 +0800
> Xiaotian Feng<dfeng@redhat.com>  wrote:
>
>> This patch introduces a new accounting flag which is set when a task
>> was killed by OOM killer. taskstats can tell users when a job has been
>> killed by the oomkiller.
>>
>
> Why is this useful?  I'd be looking for a description of some
> operational scenario where this feature is valuable to an operator?
>

users of taskstats need to know if a job is killed by OOM killer, then 
perform some automation jobs or notifications.
But current taskstats logs AXSIG if a job is killed by signal, so users 
will be confused by SIGKILL, SIGTERM or OOM killer.

> The description is incomplete.  The patch also alters the contents of
> the BSD accounting records.  That's a change to an ancient interface
> and needs a bit of exposure and thought.  Is it good to put such a
> highly linux-specific and somewhat linux-version-specific field into
> such a venerable userspace interface?
>
> If we _do_ decide to change the BSD accounting records in this manner
> then presumably a manpage will need to be updated.  A cc to
> linux-api@vger.kernel.org would be appropriate.

The BSD accounting part is not necessary, I just made it same as 
taskstats, we can drop BSD accounting part.

>
> But I'm not very convinced about this whole idea at present, personally.
>
>>   include/linux/acct.h                          |    1 +
>>   include/linux/taskstats.h                     |    2 +-
>>   kernel/acct.c                                 |    2 ++
>>   kernel/tsacct.c                               |    2 ++
>
> I'm a bit surprised that getdelays.c doesn't print ac_flag.
>
>
>