linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Michal Hocko <mhocko@kernel.org>
To: Minchan Kim <minchan@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Mel Gorman <mgorman@techsingularity.net>,
	Vlastimil Babka <vbabka@suse.cz>,
	Joonsoo Kim <iamjoonsoo.kim@lge.com>,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	Sangseok Lee <sangseok.lee@lge.com>
Subject: Re: [PATCH 3/4] mm: unreserve highatomic free pages fully before OOM
Date: Tue, 11 Oct 2016 10:01:08 +0200	[thread overview]
Message-ID: <20161011080108.GE31996@dhcp22.suse.cz> (raw)
In-Reply-To: <20161011073716.GA22314@bbox>

On Tue 11-10-16 16:37:16, Minchan Kim wrote:
> On Tue, Oct 11, 2016 at 09:26:06AM +0200, Michal Hocko wrote:
> > On Tue 11-10-16 16:09:45, Minchan Kim wrote:
[...]
> > > @@ -2154,12 +2156,24 @@ static void unreserve_highatomic_pageblock(const struct alloc_context *ac)
> > >  			 * may increase.
> > >  			 */
> > >  			set_pageblock_migratetype(page, ac->migratetype);
> > > -			move_freepages_block(zone, page, ac->migratetype);
> > > -			spin_unlock_irqrestore(&zone->lock, flags);
> > > -			return;
> > > +			ret = move_freepages_block(zone, page,
> > > +						ac->migratetype);
> > > +			/*
> > > +			 * By race with page freeing functions, !highatomic
> > > +			 * pageblocks can have free pages in highatomic free
> > > +			 * list so if drain is true, try to unreserve every
> > > +			 * free pages in highatomic free list without bailing
> > > +			 * out.
> > > +			 */
> > > +			if (!drain) {
> > 
> > 			if (ret)
> > > +				spin_unlock_irqrestore(&zone->lock, flags);
> > > +				return ret;
> > > +			}
> > 
> > arguably this would work better also for !drain case which currently
> > tries to unreserve but in case of the race it would do nothing.
> 
> I thought it but I was afraid if you say again it's over complicated.

Well, maybe there is even better/easier solution. Anyway, if
I were you I would just split it into two patches. The first
to unreserve from shoudl_reclaim_retry and the later to make
unreserve_highatomic_pageblock more reliable.

> I will do it with your SOB in next spin.

ok, thanks!
-- 
Michal Hocko
SUSE Labs

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

  reply	other threads:[~2016-10-11  8:01 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-07  5:45 [PATCH 0/4] use up highorder free pages before OOM Minchan Kim
2016-10-07  5:45 ` [PATCH 1/4] mm: adjust reserved highatomic count Minchan Kim
2016-10-07 12:30   ` Vlastimil Babka
2016-10-07 14:29     ` Minchan Kim
2016-10-10  6:57       ` Vlastimil Babka
2016-10-11  4:19         ` Minchan Kim
2016-10-11  9:40           ` Vlastimil Babka
2016-10-12  5:36           ` Mel Gorman
2016-10-07  5:45 ` [PATCH 2/4] mm: prevent double decrease of nr_reserved_highatomic Minchan Kim
2016-10-07 12:44   ` Vlastimil Babka
2016-10-07 14:30     ` Minchan Kim
2016-10-12  5:36   ` Mel Gorman
2016-10-07  5:45 ` [PATCH 3/4] mm: unreserve highatomic free pages fully before OOM Minchan Kim
2016-10-07  9:09   ` Michal Hocko
2016-10-07 14:43     ` Minchan Kim
2016-10-10  7:41       ` Michal Hocko
2016-10-11  5:01         ` Minchan Kim
2016-10-11  6:50           ` Michal Hocko
2016-10-11  7:09             ` Minchan Kim
2016-10-11  7:26               ` Michal Hocko
2016-10-11  7:37                 ` Minchan Kim
2016-10-11  8:01                   ` Michal Hocko [this message]
2016-10-07  5:45 ` [PATCH 4/4] mm: skip to reserve pageblock crossed zone boundary for HIGHATOMIC Minchan Kim
2016-10-07  9:16 ` [PATCH 0/4] use up highorder free pages before OOM Michal Hocko
2016-10-07 15:04   ` Minchan Kim
2016-10-10  7:47     ` Michal Hocko
2016-10-11  5:06       ` Minchan Kim
2016-10-11  6:53         ` Michal Hocko

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20161011080108.GE31996@dhcp22.suse.cz \
    --to=mhocko@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=iamjoonsoo.kim@lge.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mgorman@techsingularity.net \
    --cc=minchan@kernel.org \
    --cc=sangseok.lee@lge.com \
    --cc=vbabka@suse.cz \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).