From: Christoph Lameter <cl@linux.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>,
Vlastimil Babka <vbabka@suse.cz>,
Dmitry Vyukov <dvyukov@google.com>, Tejun Heo <tj@kernel.org>,
"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>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: mm: deadlock between get_online_cpus/pcpu_alloc
Date: Tue, 7 Feb 2017 10:55:51 -0600 (CST) [thread overview]
Message-ID: <alpine.DEB.2.20.1702071053380.16150@east.gentwo.org> (raw)
In-Reply-To: <20170207164130.GY5065@dhcp22.suse.cz>
On Tue, 7 Feb 2017, Michal Hocko wrote:
> I am always nervous when seeing hotplug locks being used in low level
> code. It has bitten us several times already and those deadlocks are
> quite hard to spot when reviewing the code and very rare to hit so they
> tend to live for a long time.
Yep. Hotplug events are pretty significant. Using stop_machine_XXXX() etc
would be advisable and that would avoid the taking of locks and get rid of all the
ocmplexity, reduce the code size and make the overall system much more
reliable.
Thomas?
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next prev parent reply other threads:[~2017-02-07 16:55 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
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 [this message]
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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