Re: [PATCH] mm, page_alloc: prevent infinite loop in buffered_rmqueue()

From	Mel Gorman <mgorman@techsingularity.net>
Newsgroups	linux.kernel
Subject	Re: [PATCH] mm, page_alloc: prevent infinite loop in buffered_rmqueue()
Date	2016-05-30 13:00 +0200
Message-ID	<rEt5o-33J-9@gated-at.bofh.it> (permalink)
References	<rErmW-2bT-29@gated-at.bofh.it> <rErZE-2oF-21@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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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 <vbabka@suse.cz>
> >
> >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

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[PATCH] mm, page_alloc: prevent infinite loop in buffered_rmqueue() Mel Gorman <mgorman@techsingularity.net> - 2016-05-30 11:10 +0200
  Re: [PATCH] mm, page_alloc: prevent infinite loop in  buffered_rmqueue() Vlastimil Babka <vbabka@suse.cz> - 2016-05-30 11:50 +0200
    Re: [PATCH] mm, page_alloc: prevent infinite loop in  buffered_rmqueue() Mel Gorman <mgorman@techsingularity.net> - 2016-05-30 13:00 +0200

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