From: Andrea Arcangeli <aarcange@redhat.com>
To: Minchan Kim <minchan.kim@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>, Mel Gorman <mel@csn.ul.ie>,
akpm@linux-foundation.org, Ury Stankevich <urykhy@gmail.com>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH] mm: compaction: Abort compaction if too many pages are isolated and caller is asynchronous
Date: Fri, 3 Jun 2011 00:03:56 +0200 [thread overview]
Message-ID: <20110602220356.GG2802@random.random> (raw)
In-Reply-To: <20110602205912.GA24579@barrios-laptop>
On Fri, Jun 03, 2011 at 05:59:13AM +0900, Minchan Kim wrote:
> Now that I look code more, it would meet VM_BUG_ON of get_page if the page is really
> freed. I think if we hold zone->lock to prevent prep_new_page racing, it would be okay.
There would be problems with split_huge_page too, we can't even use
get_page_unless_zero unless it's a lru page and we hold the lru_lock
and that's an hot lock too.
> But it's rather overkill so I will add my sign to your patch if we don't have better idea
> until tomorrow. :)
Things like compound_trans_head are made to protect against
split_huge_page like in ksm, not exactly to get to the head page when
the page is being freed, so it's a little tricky. If we could get to
the head page safe starting from a tail page it'd solve some issues
for memory-failure too, which is currently using compound_head unsafe
too, but at least that's running after a catastrophic hardware failure
so the safer the better but the little race is unlikely to ever be an
issue for memory-failure (and it's same issue for hugetlbfs and slub
order 3).
next prev parent reply other threads:[~2011-06-02 22:04 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-30 13:13 [PATCH] mm: compaction: Abort compaction if too many pages are isolated and caller is asynchronous Mel Gorman
2011-05-30 14:31 ` Andrea Arcangeli
2011-05-30 15:37 ` Mel Gorman
2011-05-30 16:55 ` Mel Gorman
2011-05-30 17:53 ` Andrea Arcangeli
2011-05-31 12:16 ` Minchan Kim
2011-05-31 12:24 ` Andrea Arcangeli
2011-05-31 13:33 ` Minchan Kim
2011-05-31 14:14 ` Andrea Arcangeli
2011-05-31 14:37 ` Minchan Kim
2011-05-31 14:38 ` Minchan Kim
2011-06-02 18:23 ` Andrea Arcangeli
2011-06-02 20:21 ` Minchan Kim
2011-06-02 20:59 ` Minchan Kim
2011-06-02 22:03 ` Andrea Arcangeli [this message]
2011-06-02 21:40 ` Andrea Arcangeli
2011-06-02 22:23 ` Minchan Kim
2011-06-02 22:32 ` Andrea Arcangeli
2011-06-02 23:01 ` Minchan Kim
2011-06-03 17:37 ` Andrea Arcangeli
2011-06-03 18:07 ` Andrea Arcangeli
2011-06-04 7:59 ` Minchan Kim
2011-06-06 10:32 ` Mel Gorman
2011-06-06 12:49 ` Andrea Arcangeli
2011-06-06 14:47 ` Mel Gorman
2011-06-06 14:07 ` Minchan Kim
2011-06-06 10:15 ` Mel Gorman
2011-06-06 10:26 ` Mel Gorman
2011-06-06 14:01 ` Minchan Kim
2011-06-06 14:26 ` Minchan Kim
2011-06-02 23:02 ` Minchan Kim
2011-06-01 0:57 ` Mel Gorman
2011-06-01 9:24 ` Mel Gorman
2011-06-01 17:58 ` Mel Gorman
2011-06-01 19:15 ` Andrea Arcangeli
2011-06-01 21:40 ` Mel Gorman
2011-06-01 23:30 ` Andrea Arcangeli
2011-06-02 1:03 ` Mel Gorman
2011-06-02 8:34 ` Minchan Kim
2011-06-02 13:29 ` Andrea Arcangeli
2011-06-02 14:50 ` Mel Gorman
2011-06-02 15:37 ` Andrea Arcangeli
2011-06-03 2:09 ` Mel Gorman
2011-06-03 14:49 ` Mel Gorman
2011-06-03 15:45 ` Andrea Arcangeli
2011-06-04 7:25 ` Minchan Kim
2011-06-06 10:39 ` Mel Gorman
2011-06-06 12:38 ` Andrea Arcangeli
2011-06-06 14:55 ` Mel Gorman
2011-06-06 14:19 ` Minchan Kim
2011-06-06 22:32 ` Andrew Morton
2011-06-04 6:58 ` Minchan Kim
2011-06-06 10:43 ` Mel Gorman
2011-06-06 12:40 ` Andrea Arcangeli
2011-06-06 13:27 ` Minchan Kim
2011-06-06 13:23 ` Minchan Kim
2011-05-31 14:34 ` Mel Gorman
2011-05-30 14:45 ` [stable] " Greg KH
2011-05-30 16:14 ` Minchan Kim
2011-05-31 8:32 ` Mel Gorman
2011-05-31 4:48 ` KAMEZAWA Hiroyuki
2011-05-31 5:38 ` Minchan Kim
2011-05-31 7:14 ` KOSAKI Motohiro
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