From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx157.postini.com [74.125.245.157]) by kanga.kvack.org (Postfix) with SMTP id 9F5C46B0068 for ; Fri, 28 Sep 2012 04:47:13 -0400 (EDT) Received: by obcva7 with SMTP id va7so3387489obc.14 for ; Fri, 28 Sep 2012 01:47:12 -0700 (PDT) Message-ID: <50656459.70309@ti.com> Date: Fri, 28 Sep 2012 11:48:25 +0300 From: Peter Ujfalusi MIME-Version: 1.0 Subject: Re: CMA broken in next-20120926 References: <20120927112911.GA25959@avionic-0098.mockup.avionic-design.de> <20120927151159.4427fc8f.akpm@linux-foundation.org> <20120928054330.GA27594@bbox> <20120928083722.GM3429@suse.de> In-Reply-To: <20120928083722.GM3429@suse.de> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Minchan Kim , Andrew Morton , Thierry Reding , Marek Szyprowski , Michal Nazarewicz , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Bartlomiej Zolnierkiewicz , Kyungmin Park , Mark Brown Hi, On 09/28/2012 11:37 AM, Mel Gorman wrote: >> I hope this patch fixes the bug. If this patch fixes the problem >> but has some problem about description or someone has better idea, >> feel free to modify and resend to akpm, Please. >> > > A full revert is overkill. Can the following patch be tested as a > potential replacement please? > > ---8<--- > mm: compaction: Iron out isolate_freepages_block() and isolate_freepages_range() -fix1 > > CMA is reported to be broken in next-20120926. Minchan Kim pointed out > that this was due to nr_scanned != total_isolated in the case of CMA > because PageBuddy pages are one scan but many isolations in CMA. This > patch should address the problem. > > This patch is a fix for > mm-compaction-acquire-the-zone-lock-as-late-as-possible-fix-2.patch > > Signed-off-by: Mel Gorman linux-next + this patch alone also works for me. Tested-by: Peter Ujfalusi > --- > mm/compaction.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/mm/compaction.c b/mm/compaction.c > index 8250b69..d6e260a 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -282,6 +282,7 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, > { > int nr_scanned = 0, total_isolated = 0; > struct page *cursor, *valid_page = NULL; > + unsigned long nr_strict_required = end_pfn - blockpfn; > unsigned long flags; > bool locked = false; > > @@ -343,10 +344,10 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, > > /* > * If strict isolation is requested by CMA then check that all the > - * pages scanned were isolated. If there were any failures, 0 is > + * pages requested were isolated. If there were any failures, 0 is > * returned and CMA will fail. > */ > - if (strict && nr_scanned != total_isolated) > + if (strict && nr_strict_required != total_isolated) > total_isolated = 0; > > if (locked) > -- Peter -- 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