From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f71.google.com (mail-wm0-f71.google.com [74.125.82.71]) by kanga.kvack.org (Postfix) with ESMTP id 107786B0033 for ; Wed, 18 Jan 2017 04:45:15 -0500 (EST) Received: by mail-wm0-f71.google.com with SMTP id d140so1961880wmd.4 for ; Wed, 18 Jan 2017 01:45:15 -0800 (PST) Received: from outbound-smtp02.blacknight.com (outbound-smtp02.blacknight.com. [81.17.249.8]) by mx.google.com with ESMTPS id q206si19386927wme.25.2017.01.18.01.45.13 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 18 Jan 2017 01:45:14 -0800 (PST) Received: from mail.blacknight.com (pemlinmail05.blacknight.ie [81.17.254.26]) by outbound-smtp02.blacknight.com (Postfix) with ESMTPS id 9ECCA990A8 for ; Wed, 18 Jan 2017 09:45:13 +0000 (UTC) Date: Wed, 18 Jan 2017 09:45:13 +0000 From: Mel Gorman Subject: Re: [RFC 1/4] mm, page_alloc: fix check for NULL preferred_zone Message-ID: <20170118094513.v6nlnpwnfl6pnkiv@techsingularity.net> References: <20170117221610.22505-1-vbabka@suse.cz> <20170117221610.22505-2-vbabka@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20170117221610.22505-2-vbabka@suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Vlastimil Babka Cc: Ganapatrao Kulkarni , Michal Hocko , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Tue, Jan 17, 2017 at 11:16:07PM +0100, Vlastimil Babka wrote: > Since commit c33d6c06f60f ("mm, page_alloc: avoid looking up the first zone in > a zonelist twice") we have a wrong check for NULL preferred_zone, which can > theoretically happen due to concurrent cpuset modification. We check the > zoneref pointer which is never NULL and we should check the zone pointer. > > Fixes: c33d6c06f60f ("mm, page_alloc: avoid looking up the first zone in a zonelist twice") > Signed-off-by: Vlastimil Babka Acked-by: Mel Gorman -- Mel Gorman SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org