From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f70.google.com (mail-lf0-f70.google.com [209.85.215.70]) by kanga.kvack.org (Postfix) with ESMTP id 68FB86B0260 for ; Mon, 30 May 2016 06:57:48 -0400 (EDT) Received: by mail-lf0-f70.google.com with SMTP id o70so89216040lfg.1 for ; Mon, 30 May 2016 03:57:48 -0700 (PDT) Received: from outbound-smtp05.blacknight.com (outbound-smtp05.blacknight.com. [81.17.249.38]) by mx.google.com with ESMTPS id f5si43789068wjt.204.2016.05.30.03.57.46 for (version=TLS1 cipher=AES128-SHA bits=128/128); Mon, 30 May 2016 03:57:47 -0700 (PDT) Received: from mail.blacknight.com (pemlinmail03.blacknight.ie [81.17.254.16]) by outbound-smtp05.blacknight.com (Postfix) with ESMTPS id 9B5F098C65 for ; Mon, 30 May 2016 10:57:46 +0000 (UTC) Date: Mon, 30 May 2016 11:57:45 +0100 From: Mel Gorman Subject: Re: [PATCH] mm, page_alloc: prevent infinite loop in buffered_rmqueue() Message-ID: <20160530105745.GO2527@techsingularity.net> References: <20160530090154.GM2527@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Vlastimil Babka Cc: Andrew Morton , Naoya Horiguchi , Linux-MM , LKML On Mon, May 30, 2016 at 11:46:05AM +0200, Vlastimil Babka wrote: > On 05/30/2016 11:01 AM, Mel Gorman wrote: > >From: Vlastimil Babka > > > >In DEBUG_VM kernel, we can hit infinite loop for order == 0 in > >buffered_rmqueue() when check_new_pcp() returns 1, because the bad page is > >never removed from the pcp list. Fix this by removing the page before retrying. > >Also we don't need to check if page is non-NULL, because we simply grab it from > >the list which was just tested for being non-empty. > > > >Fixes: http://www.ozlabs.org/~akpm/mmotm/broken-out/mm-page_alloc-defer-debugging-checks-of-freed-pages-until-a-pcp-drain.patch > > That was a wrong one, which I corrected later. Also it's no longer mmotm. > Correction below: > > Fixes: 479f854a207c ("mm, page_alloc: defer debugging checks of pages > allocated from the PCP") > Yes sorry, I meant to clean it up but had just re-read the patch itself, confirmed it was missing and was still required. -- 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