lkml.org 
[lkml]   [2010]   [Feb]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [patch 2/7 -mm] oom: sacrifice child with highest badness score for parent
From
On Thu, Feb 11, 2010 at 1:32 AM, David Rientjes <rientjes@google.com> wrote:
> When a task is chosen for oom kill, the oom killer first attempts to
> sacrifice a child not sharing its parent's memory instead.
> Unfortunately, this often kills in a seemingly random fashion based on
> the ordering of the selected task's child list.  Additionally, it is not
> guaranteed at all to free a large amount of memory that we need to
> prevent additional oom killing in the very near future.
>
> Instead, we now only attempt to sacrifice the worst child not sharing its
> parent's memory, if one exists.  The worst child is indicated with the
> highest badness() score.  This serves two advantages: we kill a
> memory-hogging task more often, and we allow the configurable
> /proc/pid/oom_adj value to be considered as a factor in which child to
> kill.
>
> Reviewers may observe that the previous implementation would iterate
> through the children and attempt to kill each until one was successful
> and then the parent if none were found while the new code simply kills
> the most memory-hogging task or the parent.  Note that the only time
> oom_kill_task() fails, however, is when a child does not have an mm or
> has a /proc/pid/oom_adj of OOM_DISABLE.  badness() returns 0 for both
> cases, so the final oom_kill_task() will always succeed.
>
> Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>

Regardless of forkbom detection, It does makes sense to me.

--
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: 2010-02-13 04:23    [from the cache]
©2003-2011 Jasper Spaans