From: Dmitry Vyukov <dvyukov@google.com>
To: Vlastimil Babka <vbabka@suse.cz>
Cc: Tejun Heo <tj@kernel.org>, Christoph Lameter <cl@linux.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
syzkaller <syzkaller@googlegroups.com>,
Mel Gorman <mgorman@techsingularity.net>,
Michal Hocko <mhocko@suse.cz>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: mm: deadlock between get_online_cpus/pcpu_alloc
Date: Mon, 30 Jan 2017 16:48:08 +0100 [thread overview]
Message-ID: <CACT4Y+ZT+_L3deDUcmBkr_Pr3KdCdLv6ON=2QHbK5YnBxJfLDg@mail.gmail.com> (raw)
In-Reply-To: <c7658ace-23ae-227a-2ea9-7e6bd1c8c761@suse.cz>
On Sun, Jan 29, 2017 at 6:22 PM, Vlastimil Babka <vbabka@suse.cz> wrote:
> On 29.1.2017 13:44, Dmitry Vyukov wrote:
>> Hello,
>>
>> I've got the following deadlock report while running syzkaller fuzzer
>> on f37208bc3c9c2f811460ef264909dfbc7f605a60:
>>
>> [ INFO: possible circular locking dependency detected ]
>> 4.10.0-rc5-next-20170125 #1 Not tainted
>> -------------------------------------------------------
>> syz-executor3/14255 is trying to acquire lock:
>> (cpu_hotplug.dep_map){++++++}, at: [<ffffffff814271c7>]
>> get_online_cpus+0x37/0x90 kernel/cpu.c:239
>>
>> but task is already holding lock:
>> (pcpu_alloc_mutex){+.+.+.}, at: [<ffffffff81937fee>]
>> pcpu_alloc+0xbfe/0x1290 mm/percpu.c:897
>>
>> which lock already depends on the new lock.
>
> I suspect the dependency comes from recent changes in drain_all_pages(). They
> were later redone (for other reasons, but nice to have another validation) in
> the mmots patch [1], which AFAICS is not yet in mmotm and thus linux-next. Could
> you try if it helps?
It happened only once on linux-next, so I can't verify the fix. But I
will watch out for other occurrences.
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next prev parent reply other threads:[~2017-01-30 15:48 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-29 12:44 Dmitry Vyukov
2017-01-29 17:22 ` Vlastimil Babka
2017-01-30 15:48 ` Dmitry Vyukov [this message]
2017-02-06 19:13 ` Dmitry Vyukov
2017-02-06 22:05 ` Mel Gorman
2017-02-07 8:48 ` Michal Hocko
2017-02-07 9:23 ` Vlastimil Babka
2017-02-07 9:46 ` Mel Gorman
2017-02-07 9:53 ` Michal Hocko
2017-02-07 10:42 ` Mel Gorman
2017-02-07 11:13 ` Mel Gorman
2017-02-07 9:43 ` Mel Gorman
2017-02-07 9:49 ` Vlastimil Babka
2017-02-07 10:05 ` Michal Hocko
2017-02-07 10:28 ` Mel Gorman
2017-02-07 10:35 ` Michal Hocko
2017-02-07 11:34 ` Mel Gorman
2017-02-07 11:43 ` Michal Hocko
2017-02-07 11:54 ` Vlastimil Babka
2017-02-07 12:08 ` Michal Hocko
2017-02-07 12:37 ` Michal Hocko
2017-02-07 12:43 ` Vlastimil Babka
2017-02-07 12:48 ` Michal Hocko
2017-02-07 13:57 ` Vlastimil Babka
2017-02-07 13:58 ` Mel Gorman
2017-02-07 14:19 ` Michal Hocko
2017-02-07 15:34 ` Michal Hocko
2017-02-07 16:22 ` Mel Gorman
2017-02-07 16:41 ` Michal Hocko
2017-02-07 16:55 ` Christoph Lameter
2017-02-07 22:25 ` Thomas Gleixner
2017-02-08 7:35 ` Michal Hocko
2017-02-08 12:02 ` Thomas Gleixner
2017-02-08 12:21 ` Michal Hocko
2017-02-08 12:26 ` Mel Gorman
2017-02-08 13:23 ` Thomas Gleixner
2017-02-08 14:03 ` Mel Gorman
2017-02-08 14:11 ` Peter Zijlstra
2017-02-08 15:11 ` Christoph Lameter
2017-02-08 15:21 ` Michal Hocko
2017-02-08 16:17 ` Christoph Lameter
2017-02-08 17:46 ` Thomas Gleixner
2017-02-09 3:15 ` Christoph Lameter
2017-02-09 11:42 ` Thomas Gleixner
2017-02-09 14:00 ` Christoph Lameter
2017-02-09 14:53 ` Thomas Gleixner
2017-02-09 15:42 ` Christoph Lameter
2017-02-09 16:12 ` Thomas Gleixner
2017-02-09 17:22 ` Christoph Lameter
2017-02-09 17:40 ` Thomas Gleixner
2017-02-09 19:15 ` Michal Hocko
2017-02-10 17:58 ` Christoph Lameter
2017-02-08 15:06 ` Christoph Lameter
2017-02-07 17:03 ` Tejun Heo
2017-02-07 20:16 ` Michal Hocko
2017-02-07 13:03 ` Mel Gorman
2017-02-07 13:48 ` Michal Hocko
2017-02-07 11:24 ` Tetsuo Handa
2017-02-07 8:43 ` Michal Hocko
2017-02-07 21:53 ` Thomas Gleixner
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