From: Mel Gorman <mgorman@techsingularity.net>
To: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mm, page_alloc: prevent infinite loop in buffered_rmqueue()
Date: Mon, 30 May 2016 11:57:45 +0100 [thread overview]
Message-ID: <20160530105745.GO2527@techsingularity.net> (raw)
In-Reply-To: <a4da34ff-cda2-a9a9-d586-277eb6f8797e@suse.cz>
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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WARNING: multiple messages have this Message-ID (diff)
From: Mel Gorman <mgorman@techsingularity.net>
To: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mm, page_alloc: prevent infinite loop in buffered_rmqueue()
Date: Mon, 30 May 2016 11:57:45 +0100 [thread overview]
Message-ID: <20160530105745.GO2527@techsingularity.net> (raw)
In-Reply-To: <a4da34ff-cda2-a9a9-d586-277eb6f8797e@suse.cz>
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
next prev parent reply other threads:[~2016-05-30 10:57 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-30 9:01 [PATCH] mm, page_alloc: prevent infinite loop in buffered_rmqueue() Mel Gorman
2016-05-30 9:01 ` Mel Gorman
2016-05-30 9:46 ` Vlastimil Babka
2016-05-30 9:46 ` Vlastimil Babka
2016-05-30 10:57 ` Mel Gorman [this message]
2016-05-30 10:57 ` Mel Gorman
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