Re: [patch v3] mm, oom: do not schedule if current has been killed

[Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>]

(2012/06/20 6:39), KOSAKI Motohiro wrote:
> (6/19/12 4:58 PM), David Rientjes wrote:
>> The oom killer currently schedules away from current in an
>> uninterruptible sleep if it does not have access to memory reserves.
>> It's possible that current was killed because it shares memory with the
>> oom killed thread or because it was killed by the user in the interim,
>> however.
>>
>> This patch only schedules away from current if it does not have a pending
>> kill, i.e. if it does not share memory with the oom killed thread.  It's
>> possible that it will immediately retry its memory allocation and fail,
>> but it will immediately be given access to memory reserves if it calls
>> the oom killer again.
>>
>> This prevents the delay of memory freeing when threads that share memory
>> with the oom killed thread get unnecessarily scheduled.
>>
>> Signed-off-by: David Rientjes<rientjes@google.com>
>> ---
>>   mm/oom_kill.c |   11 +++++------
>>   1 file changed, 5 insertions(+), 6 deletions(-)
>>
>> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
>> --- a/mm/oom_kill.c
>> +++ b/mm/oom_kill.c
>> @@ -746,11 +746,11 @@ out:
>>   	read_unlock(&tasklist_lock);
>>
>>   	/*
>> -	 * Give "p" a good chance of killing itself before we
>> -	 * retry to allocate memory unless "p" is current
>> +	 * Give the killed threads a good chance of exiting before trying to
>> +	 * allocate memory again.
>>   	 */
>> -	if (killed&&  !test_thread_flag(TIF_MEMDIE))
>> -		schedule_timeout_uninterruptible(1);
>> +	if (killed)
>> +		schedule_timeout_killable(1);
>>   }
>
> This is not match I expected. but I have no seen a big problem.
>
> Acked-by: KOSAKI Motohiro<kosaki.motohiro@jp.fujitsu.com>
>

Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

I'll check memcg part to make it consistent to this when this goes to -mm.




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