On Wed, 17 Feb 2010, Minchan Kim wrote: > If we found current task is existing but didn't set TIF_MEMDIE > during OOM victim selection, let's stop unnecessary looping for > getting high badness score task and go ahead for killing current. > > This patch would make side effect skip OOM_DISABLE test. > But It's okay since the task is existing and oom_kill_process > doesn't show any killing message since __oom_kill_task will > interrupt it in oom_kill_process. > > Signed-off-by: Minchan Kim <minchan.kim@xxxxxxxxx> > Cc: Nick Piggin <npiggin@xxxxxxx> > --- > mm/oom_kill.c | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) > > diff --git a/mm/oom_kill.c b/mm/oom_kill.c > index 3618be3..5c21398 100644 > --- a/mm/oom_kill.c > +++ b/mm/oom_kill.c > @@ -295,6 +295,7 @@ static struct task_struct > *select_bad_process(unsigned long *ppoints, > > chosen = p; > *ppoints = ULONG_MAX; > + break; > } > > if (p->signal->oom_adj == OOM_DISABLE) No, we don't want to break because there may be other candidate tasks that have TIF_MEMDIE set that will be detected if we keep scanning. Returning ERR_PTR(-1UL) from select_bad_process() has a special meaning: it means we return to the page allocator without doing anything. We don't want more than one candidate task to ever have TIF_MEMDIE at a time, otherwise they can deplete all memory reserves and not make any forward progress. So we always have to iterate the entire tasklist unless we find an already oom killed task with access to memory reserves (to prevent needlessly killing additional tasks before the first had a chance to exit and free its memory) or a different candidate task is exiting so we'll be freeing memory shortly (or it will be invoking the oom killer itself as current and then get chosen as the victim). -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>