From: Rik van Riel <riel@redhat.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>,
Andrew Morton <akpm@linux-foundation.org>,
Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
Minchan Kim <minchan.kim@gmail.com>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Christoph Lameter <cl@linux.com>,
Andrea Arcangeli <aarcange@redhat.com>
Subject: Re: [PATCH 1/2] mm,migration: Prevent rmap_walk_[anon|ksm] seeing the wrong VMA information
Date: Thu, 06 May 2010 09:40:56 -0400 [thread overview]
Message-ID: <4BE2C6E8.2030609@redhat.com> (raw)
In-Reply-To: <alpine.LFD.2.00.1005051007140.27218@i5.linux-foundation.org>
On 05/05/2010 01:34 PM, Linus Torvalds wrote:
> - you always lock the _deepest_ anon_vma you can find.
The emphasis should be on "always" :)
> That means just a single lock. And the "deepest" anon_vma is well-defined
> for all anon_vma's, because each same_anon_vma chain is always rooted in
> the original anon_vma that caused it.
It should work, but only if we always take the deepest
anon_vma lock.
Not just in the migration code, but also in mmap, munmap,
mprotect (for split_vma), expand_stack, etc...
Otherwise we will still not provide exclusion of migrate
vs. those events.
I'm guessing that means changing both anon_vma_lock and
page_lock_anon_vma to always take the deepest anon_vma
lock - not introducing a new function that is only called
by the migration code.
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next prev parent reply other threads:[~2010-05-06 13:41 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-05 13:14 [PATCH 0/2] Fix migration races in rmap_walk() V5 Mel Gorman
2010-05-05 13:14 ` [PATCH 1/2] mm,migration: Prevent rmap_walk_[anon|ksm] seeing the wrong VMA information Mel Gorman
2010-05-05 14:34 ` Linus Torvalds
2010-05-05 14:56 ` Mel Gorman
2010-05-05 15:31 ` Linus Torvalds
2010-05-05 15:54 ` Mel Gorman
2010-05-05 16:13 ` Andrea Arcangeli
2010-05-05 19:11 ` Peter Zijlstra
2010-05-05 19:57 ` Andrea Arcangeli
2010-05-21 0:27 ` Andrea Arcangeli
2010-05-06 10:37 ` Mel Gorman
2010-05-05 17:34 ` Linus Torvalds
2010-05-05 17:57 ` Linus Torvalds
2010-05-05 18:14 ` Mel Gorman
2010-05-05 18:34 ` Linus Torvalds
2010-05-06 11:03 ` Mel Gorman
2010-05-06 13:40 ` Rik van Riel [this message]
2010-05-06 13:45 ` Mel Gorman
2010-05-05 17:53 ` Mel Gorman
2010-05-05 18:02 ` Linus Torvalds
2010-05-05 18:17 ` Mel Gorman
2010-05-06 0:22 ` Mel Gorman
2010-05-06 0:42 ` Linus Torvalds
2010-05-06 10:02 ` Mel Gorman
2010-05-06 14:15 ` Linus Torvalds
2010-05-06 14:25 ` Mel Gorman
2010-05-06 9:47 ` Minchan Kim
2010-05-06 9:54 ` Mel Gorman
2010-05-06 10:01 ` Minchan Kim
2010-05-06 10:10 ` Mel Gorman
2010-05-06 14:06 ` Linus Torvalds
2010-05-06 15:59 ` Minchan Kim
2010-05-06 7:38 ` KAMEZAWA Hiroyuki
2010-05-06 9:46 ` Mel Gorman
2010-05-06 23:52 ` KAMEZAWA Hiroyuki
2010-05-07 5:49 ` KAMEZAWA Hiroyuki
2010-05-05 13:14 ` [PATCH 2/2] mm,migration: Fix race between shift_arg_pages and rmap_walk by guaranteeing rmap_walk finds PTEs created within the temporary stack Mel Gorman
-- strict thread matches above, loose matches on Subject: below --
2010-05-06 15:33 [PATCH 0/2] Fix migration races in rmap_walk() V6 Mel Gorman
2010-05-06 15:33 ` [PATCH 1/2] mm,migration: Prevent rmap_walk_[anon|ksm] seeing the wrong VMA information Mel Gorman
2010-05-06 15:44 ` Rik van Riel
2010-05-06 15:51 ` Mel Gorman
2010-05-06 15:59 ` Linus Torvalds
2010-05-06 17:07 ` Mel Gorman
2010-05-06 23:20 [PATCH 0/2] Fix migration races in rmap_walk() V7 Mel Gorman
2010-05-06 23:20 ` [PATCH 1/2] mm,migration: Prevent rmap_walk_[anon|ksm] seeing the wrong VMA information Mel Gorman
2010-05-07 0:56 ` KAMEZAWA Hiroyuki
2010-05-07 16:26 ` Mel Gorman
2010-05-08 15:39 ` Andrea Arcangeli
2010-05-08 17:02 ` Linus Torvalds
2010-05-08 18:04 ` Andrea Arcangeli
2010-05-08 19:51 ` Linus Torvalds
2010-05-09 19:23 ` Mel Gorman
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