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 16:56:11 -0700 [thread overview]
Message-ID: <BANLkTinoFnTjCDL8B2HEYdYHqbMgCw_RrQ@mail.gmail.com> (raw)
In-Reply-To: <BANLkTinsq-XJGvRVmBa6kRp0RTj9NqGWtA@mail.gmail.com>
On Sat, May 28, 2011 at 4:24 PM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> 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.
Thinking some more about it, I end up agreeing with the whole patch.
The "page_mapped()" test is what we use in the slow-path after
incrementing the anon_vma count too when the trylock didn't work too,
so it can't be too wrong.
So I'm going to apply it as-is as an improvement (at least we won't be
unlocking the wrong anon_vma root), and hope that you and Peter end up
agreeing about what the sufficient test is for whether the anon_vma is
the right one.
Linus
--
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/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2011-05-28 23:56 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-28 20:20 [PATCH] mm: fix page_lock_anon_vma leaving mutex locked Hugh Dickins
2011-05-28 21:14 ` Peter Zijlstra
2011-05-28 22:02 ` Hugh Dickins
2011-05-28 23:24 ` Linus Torvalds
2011-05-28 23:56 ` Linus Torvalds [this message]
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
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=BANLkTinoFnTjCDL8B2HEYdYHqbMgCw_RrQ@mail.gmail.com \
--to=torvalds@linux-foundation.org \
--cc=a.p.zijlstra@chello.nl \
--cc=akpm@linux-foundation.org \
--cc=hughd@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
/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).