From: Linus Torvalds <torvalds@linux-foundation.org>
To: Hugh Dickins <hughd@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH] mm: fix page_lock_anon_vma leaving mutex locked
Date: Sat, 28 May 2011 16:24:42 -0700 [thread overview]
Message-ID: <BANLkTinsq-XJGvRVmBa6kRp0RTj9NqGWtA@mail.gmail.com> (raw)
In-Reply-To: <alpine.LSU.2.00.1105281437320.13942@sister.anvils>
On Sat, May 28, 2011 at 3:02 PM, Hugh Dickins <hughd@google.com> wrote:
>
> But I'm replying before I've given it enough thought,
> mainly to let you know that I am back on it now.
So I applied your other two patches as obvious, but not this one.
I'm wondering - wouldn't it be nicer to just re-check (after getting
the anon_vma lock) that page->mapping still matches anon_mapping?
That said, I do agree with the "anon_vma_root" part of your patch. I
just think you mixed up two independent issues with it: the fact that
we may be unlocking a new root, and the precise check used to
determine whether the anon_vma might have changed.
So my gut feeling is that we should do the "anon_vma" root thing
independently as a fix for the "maybe anon_vma->root changed" issue,
and then as a separate patch decide on how to check whether anon_vma
is still valid.
Hmm?
Linus
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next prev parent reply other threads:[~2011-05-28 23:25 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-28 20:20 Hugh Dickins
2011-05-28 21:14 ` Peter Zijlstra
2011-05-28 22:02 ` Hugh Dickins
2011-05-28 23:24 ` Linus Torvalds [this message]
2011-05-28 23:56 ` Linus Torvalds
2011-05-29 0:12 ` Hugh Dickins
2011-05-29 0:23 ` Linus Torvalds
2011-05-29 0:43 ` Hugh Dickins
2011-05-29 8:35 ` Peter Zijlstra
2011-05-29 8:33 ` Peter Zijlstra
2011-05-29 20:53 ` Hugh Dickins
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