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Date: Thu, 28 Aug 2014 10:31:26 -0500 (CDT)
From: Christoph Lameter <cl@linux.com>
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To: Sasha Levin <sasha.levin@oracle.com>
cc: Pekka Enberg <penberg@kernel.org>, David Rientjes <rientjes@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>,
        "davej @gmail-imap.l.google.com>> Dave Jones" <davej@redhat.com>
Subject: Re: mm: slub: circular dependency between slab_mutex and
 cpu_hotplug
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On Thu, 28 Aug 2014, Sasha Levin wrote:

> While fuzzing with trinity inside a KVM tools guest running the latest -next
> kernel, I've stumbled on the following spew:

This looks to me more to be a cpu hotplug issue.
>
> [ 7841.323177]  Possible unsafe locking scenario:
> [ 7841.323177]
> [ 7841.323177]        CPU0                    CPU1
> [ 7841.323177]        ----                    ----
> [ 7841.323177]   lock(cpu_hotplug.lock#2);
> [ 7841.323177]                                lock((oom_notify_list).rwsem);
> [ 7841.323177]                                lock(cpu_hotplug.lock#2);
> [ 7841.323177]   lock(slab_mutex);