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Subject: Re: Softlockup during memory allocation
References: <e3177ea6-a921-dac9-f4f3-952c14e2c4df@kyup.com>
From: Vlastimil Babka <vbabka@suse.cz>
Message-ID: <89ee3413-71a3-403d-48fa-af325d40f8db@suse.cz>
Date: Wed, 2 Nov 2016 20:00:31 +0100
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Sender: owner-linux-mm@kvack.org
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To: Nikolay Borisov <kernel@kyup.com>, Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>, Linux MM <linux-mm@kvack.org>, "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>

On 11/01/2016 09:12 AM, Nikolay Borisov wrote:
> In addition to that I believe there is something wrong
> with the NR_PAGES_SCANNED stats since they are being negative. 
> I haven't looked into the code to see how this value is being 
> synchronized and if there is a possibility of it temporary going negative. 

This is because there's a shared counter and percpu diffs, and crash
only looks at the shared counter.

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