lkml.org 
[lkml]   [2011]   [Mar]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH 3/5] oom: create oom autogroup
From
On Tue, Mar 22, 2011 at 8:08 PM, KOSAKI Motohiro
<kosaki.motohiro@jp.fujitsu.com> wrote:
> When plenty processes (eg fork bomb) are running, the TIF_MEMDIE task
> never exit, at least, human feel it's never. therefore kernel become
> hang-up.
>
> "perf sched" tell us a hint.
>
>  ------------------------------------------------------------------------------
>  Task                  |   Runtime ms  | Average delay ms | Maximum delay ms |
>  ------------------------------------------------------------------------------
>  python:1754           |      0.197 ms | avg: 1731.727 ms | max: 3433.805 ms |
>  python:1843           |      0.489 ms | avg: 1707.433 ms | max: 3622.955 ms |
>  python:1715           |      0.220 ms | avg: 1707.125 ms | max: 3623.246 ms |
>  python:1818           |      2.127 ms | avg: 1527.331 ms | max: 3622.553 ms |
>  ...
>  ...
>
> Processes flood makes crazy scheduler delay. and then the victim process
> can't run enough. Grr. Should we do?
>
> Fortunately, we already have anti process flood framework, autogroup!
> This patch reuse this framework and avoid kernel live lock.

That's cool idea but I have a concern.

You remove boosting priority in [2/5] and move victim tasks into autogroup.
If I understand autogroup right, victim process and threads in the
process take less schedule chance than now.

Could it make unnecessary killing of other tasks?
I am not sure. Just out of curiosity.

Thanks for nice work, Kosaki.
--
Kind regards,
Minchan Kim
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2011-03-23 00:23    [W:0.185 / U:4.320 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site