From: Oleg Nesterov <oleg@redhat.com>
To: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Hugh Dickins <hughd@google.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>,
"kamezawa.hiroyu@jp.fujitsu.com" <kamezawa.hiroyu@jp.fujitsu.com>,
"markus@trippelsdorf.de" <markus@trippelsdorf.de>,
"stable@vger.kernel.org" <stable@vger.kernel.org>
Subject: Re: [patch 12/12] mm: correctly synchronize rss-counters at exit/exec
Date: Fri, 8 Jun 2012 19:01:52 +0200 [thread overview]
Message-ID: <20120608170152.GA30975@redhat.com> (raw)
In-Reply-To: <4FD1FE20.40600@openvz.org>
On 06/08, Konstantin Khlebnikov wrote:
>
> Oleg Nesterov wrote:
>> On 06/08, Konstantin Khlebnikov wrote:
>>>
>>> As result you can see "BUG: Bad rss-counter state mm:ffff88040783a680 idx:1 val:-1" in dmesg
>>>
>>> There left only one problem: nobody calls sync_mm_rss() after put_user() in mm_release().
>>
>> Both callers call sync_mm_rss() to make check_mm() happy. But please
>> see the changelog, I think we should move it into mm_release(). See
>> the patch below (on top of v2 I sent). I need to recheck.
>
> Patch below broken: it removes one hunk from kernel/exit.c twice.
> And it does not add anything into mm_release().
Yes, sorry. But I guess you understand the intent, mm_release() should
simply do sync_mm_rss() after put_user(clear_child_tid) unconditionally.
If task->mm == NULL but task->rss_stat, then there is something wrong
and probably OOPS makes sense.
Oleg.
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next prev parent reply other threads:[~2012-06-08 17:03 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20120607212114.E4F5AA02F8@akpm.mtv.corp.google.com>
[not found] ` <CA+55aFxOWR_h1vqRLAd_h5_woXjFBLyBHP--P8F7WsYrciXdmA@mail.gmail.com>
2012-06-08 0:25 ` Linus Torvalds
2012-06-08 1:05 ` Markus Trippelsdorf
2012-06-08 1:18 ` Linus Torvalds
2012-06-08 12:18 ` Oleg Nesterov
2012-06-11 10:25 ` Kamezawa Hiroyuki
2012-06-08 1:16 ` Hugh Dickins
2012-06-08 1:19 ` Linus Torvalds
2012-06-08 5:28 ` Hugh Dickins
2012-06-08 10:20 ` Konstantin Khlebnikov
2012-06-08 12:24 ` Oleg Nesterov
2012-06-08 13:29 ` Konstantin Khlebnikov
2012-06-08 17:01 ` Oleg Nesterov [this message]
2012-06-09 9:43 ` [PATCH] " Konstantin Khlebnikov
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