From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx102.postini.com [74.125.245.102]) by kanga.kvack.org (Postfix) with SMTP id AB1826B0068 for ; Fri, 28 Sep 2012 02:11:11 -0400 (EDT) Date: Fri, 28 Sep 2012 08:10:56 +0200 From: Thierry Reding Subject: Re: CMA broken in next-20120926 Message-ID: <20120928061056.GA13458@avionic-0098.mockup.avionic-design.de> References: <20120927112911.GA25959@avionic-0098.mockup.avionic-design.de> <20120927151159.4427fc8f.akpm@linux-foundation.org> <20120928054330.GA27594@bbox> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="RnlQjJ0d97Da+TV1" Content-Disposition: inline In-Reply-To: <20120928054330.GA27594@bbox> Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Andrew Morton , Marek Szyprowski , Michal Nazarewicz , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Bartlomiej Zolnierkiewicz , Kyungmin Park , Mark Brown , Peter Ujfalusi , Mel Gorman --RnlQjJ0d97Da+TV1 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Sep 28, 2012 at 02:43:30PM +0900, Minchan Kim wrote: > On Thu, Sep 27, 2012 at 03:11:59PM -0700, Andrew Morton wrote: > > On Thu, 27 Sep 2012 13:29:11 +0200 > > Thierry Reding wrote: > >=20 > > > Hi Marek, > > >=20 > > > any idea why CMA might be broken in next-20120926. I see that there > > > haven't been any major changes to CMA itself, but there's been quite a > > > bit of restructuring of various memory allocation bits lately. I wasn= 't > > > able to track the problem down, though. > > >=20 > > > What I see is this during boot (with CMA_DEBUG enabled): > > >=20 > > > [ 0.266904] cma: dma_alloc_from_contiguous(cma db474f80, count 64,= align 6) > > > [ 0.284469] cma: dma_alloc_from_contiguous(): memory range at c09d= 7000 is busy, retrying > > > [ 0.293648] cma: dma_alloc_from_contiguous(): memory range at c09d= 7800 is busy, retrying > > > ... > > > [ 2.648619] DMA: failed to allocate 256 KiB pool for atomic cohere= nt allocation > > > ... > > > [ 4.196193] WARNING: at /home/thierry.reding/src/kernel/linux-ipmp= =2Egit/arch/arm/mm/dma-mapping.c:485 __alloc_from_pool+0xdc/0x110() > > > [ 4.207988] coherent pool not initialised! > > >=20 > > > So the pool isn't getting initialized properly because CMA can't get = at > > > the memory. Do you have any hints as to what might be going on? If it= 's > > > any help, I started seeing this with next-20120926 and it is in today= 's > > > next as well. > > >=20 > >=20 > > Bart and Minchan have made recent changes to CMA. Let us cc them. >=20 > Hi all, >=20 > I have no time now so I look over the problem during short time > so I mighte be wrong. Even I should leave the office soon and > Korea will have long vacation from now on so I will be off by next week. > So it's hard to reach on me. >=20 > 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. >=20 > Thierry, Could you test below patch? >=20 > >From 24a547855fa2bd4212a779cc73997837148310b3 Mon Sep 17 00:00:00 2001 > From: Minchan Kim > Date: Fri, 28 Sep 2012 14:28:32 +0900 > Subject: [PATCH] revert mm: compaction: iron out isolate_freepages_block() > and isolate_freepages_range() >=20 > [1] made bug on CMA. > The nr_scanned should be never equal to total_isolated for successful CMA. > This patch reverts part of the patch. >=20 > [1] mm: compaction: iron out isolate_freepages_block() and isolate_freepa= ges_range() >=20 > Cc: Mel Gorman > Signed-off-by: Minchan Kim > --- > mm/compaction.c | 29 ++++++++++++++++------------- > 1 file changed, 16 insertions(+), 13 deletions(-) With that patch applied I see this now: [ 0.255177] DMA: preallocated 256 KiB pool for atomic coherent allocatio= ns so this fixes the bug for me. Tested-by: Thierry Reding --RnlQjJ0d97Da+TV1 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) iQIcBAEBAgAGBQJQZT9wAAoJEN0jrNd/PrOhZs0P/R88ms+xrV16gEOjEshUz2Jn A1apn4OJxuQ7PzaFObQn4p0FgXmfCNP/Yd8c7hVotL4ciVjXuUtaeK8OnzNpWz5m 2MGbSCIzitvYijnNn0ph1cS5vbTDU2sBJY8RlqYjG8H1+lM/ISRV+5cWXh0R7wsd mb1k/snsehVZ9xDxkrAz7o+KD8Gm6y7Yn0R060UfQH+5XmjdUM5/KIP3shg4IVKR Gg9b9mAc2wNWmE6Anu+jRM6ktQ1HXz4IkMgstf1NSZ25XtwqPDoBeH+vl0l80mrr 3LMe0YyRbscgD3hmprWZ5nzRCkbPGxZApbNO3h2kZS625vW0exYwzR+yIXEb9GpK vR3pBineuAHE1Qzydl8oH83qWYXlEupvqF5Gs10aTdq1YIemWJ6n9ldEACyVqCsZ lfSPO23D8e72ozzQOnM0m48+om+ntNBKQMaedSbRgpMjkQ7Yd2g0mB1SgJy9fMlZ ynqIxCoWvojr76BxlWdZE1I6tqBWdgJSmSuscI35XrGCe/Tw3RgdOT1b+OphbvuJ u+JZu7F9EIdvLmQT3At+brvLao3lsVlvdETQBJExQiyKwmIjSB1q5L/wmBKSLwo8 xK2dBXV0rq6EA6UWVrHklxFpcZQDmPnLZUA1H/lQWzekiDw300ghXo5pNjcw1GzR pEePJwXuUppkT90NWHme =bgcT -----END PGP SIGNATURE----- --RnlQjJ0d97Da+TV1-- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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