From: Markus Trippelsdorf <markus@trippelsdorf.de>
To: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Hugh Dickins <hughd@google.com>,
KOSAKI Motohiro <kosaki.motohiro@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mm: sync rss-counters at the end of exit_mm()
Date: Tue, 10 Apr 2012 18:04:57 +0200 [thread overview]
Message-ID: <20120410160457.GA346@x4> (raw)
In-Reply-To: <4F83D470.6010207@openvz.org>
On 2012.04.10 at 10:34 +0400, Konstantin Khlebnikov wrote:
> Hugh Dickins wrote:
> > On Mon, 9 Apr 2012, KOSAKI Motohiro wrote:
> >> On Mon, Apr 9, 2012 at 4:03 PM, Konstantin Khlebnikov
> >> <khlebnikov@openvz.org> wrote:
> >>> On task's exit do_exit() calls sync_mm_rss() but this is not enough,
> >>> there can be page-faults after this point, for example exit_mm() ->
> >>> mm_release() -> put_user() (for processing tsk->clear_child_tid).
> >>> Thus there may be some rss-counters delta in current->rss_stat.
> >>
> >> Seems reasonable.
> >
> > Yes, I think Konstantin has probably caught it;
> > but I'd like to hear confirmation from Markus.
>
> There is another bug in exec_mmap()
>
> --- a/fs/exec.c
> +++ b/fs/exec.c
> @@ -823,8 +823,8 @@ static int exec_mmap(struct mm_struct *mm)
> /* Notify parent that we're no longer interested in the old VM */
> tsk = current;
> old_mm = current->mm;
> - sync_mm_rss(old_mm);
> mm_release(tsk, old_mm);
> + sync_mm_rss(old_mm);
>
> if (old_mm) {
> /*
FWIW with both patches applied I cannot reproduce the issue anymore.
Thanks.
--
Markus
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next prev parent reply other threads:[~2012-04-10 16:05 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-09 20:03 [PATCH] mm: sync rss-counters at the end of exit_mm() Konstantin Khlebnikov
2012-04-09 21:04 ` KOSAKI Motohiro
2012-04-09 22:03 ` Hugh Dickins
2012-04-10 0:33 ` KAMEZAWA Hiroyuki
2012-04-10 6:34 ` Konstantin Khlebnikov
2012-04-10 16:04 ` Markus Trippelsdorf [this message]
2012-04-10 0:35 ` KAMEZAWA Hiroyuki
2012-04-10 5:43 ` Konstantin Khlebnikov
2012-04-10 17:07 ` [PATCH v2] mm: correctly synchronize rss-counters at exit/exec Konstantin Khlebnikov
2012-04-10 18:43 ` Andrew Morton
2012-04-10 19:52 ` Konstantin Khlebnikov
2012-04-10 19:10 ` Oleg Nesterov
2012-04-10 20:09 ` Konstantin Khlebnikov
2012-04-12 8:09 ` [PATCH 1/2] mm: set task exit code before complete_vfork_done() Konstantin Khlebnikov
2012-04-12 23:35 ` Andrew Morton
2012-04-12 23:54 ` Oleg Nesterov
2012-04-20 17:59 ` Oleg Nesterov
2012-04-20 19:23 ` Konstantin Khlebnikov
2012-04-20 20:41 ` Oleg Nesterov
2012-04-25 20:01 ` Andrew Morton
2012-04-12 8:09 ` [PATCH 2/2] mm: call complete_vfork_done() after clearing child_tid and flushing rss-counters Konstantin Khlebnikov
2012-04-12 23:39 ` Andrew Morton
2012-04-13 6:43 ` Konstantin Khlebnikov
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