lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Thu, 22 Nov 2012 13:55:23 +0100 From: Marek Szyprowski <m.szyprowski@...sung.com> To: Andrew Morton <akpm@...ux-foundation.org> Cc: linux-arm-kernel@...ts.infradead.org, linaro-mm-sig@...ts.linaro.org, linux-mm@...ck.org, linux-kernel@...r.kernel.org, Kyungmin Park <kyungmin.park@...sung.com>, Arnd Bergmann <arnd@...db.de>, Soren Moch <smoch@....de>, Thomas Petazzoni <thomas.petazzoni@...e-electrons.com>, Sebastian Hesselbarth <sebastian.hesselbarth@...il.com>, Andrew Lunn <andrew@...n.ch>, Jason Cooper <jason@...edaemon.net>, KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>, Michal Hocko <mhocko@...e.cz>, Mel Gorman <mgorman@...e.de> Subject: Re: [PATCH v2] mm: dmapool: use provided gfp flags for all dma_alloc_coherent() calls On 11/21/2012 8:17 PM, Andrew Morton wrote: > On Wed, 21 Nov 2012 10:20:07 +0100 > Marek Szyprowski <m.szyprowski@...sung.com> wrote: > > On 11/21/2012 9:36 AM, Andrew Morton wrote: > > > On Wed, 21 Nov 2012 09:08:52 +0100 Marek Szyprowski <m.szyprowski@...sung.com> wrote: > > > > On 11/20/2012 8:33 PM, Andrew Morton wrote: > > > > > On Tue, 20 Nov 2012 15:31:45 +0100 > > > > > Marek Szyprowski <m.szyprowski@...sung.com> wrote: > > > > > > > > > > > dmapool always calls dma_alloc_coherent() with GFP_ATOMIC flag, > > > > > > regardless the flags provided by the caller. This causes excessive > > > > > > pruning of emergency memory pools without any good reason. Additionaly, > > > > > > on ARM architecture any driver which is using dmapools will sooner or > > > > > > later trigger the following error: > > > > > > "ERROR: 256 KiB atomic DMA coherent pool is too small! > > > > > > Please increase it with coherent_pool= kernel parameter!". > > > > > > Increasing the coherent pool size usually doesn't help much and only > > > > > > delays such error, because all GFP_ATOMIC DMA allocations are always > > > > > > served from the special, very limited memory pool. > > > > > > > > > > > > > > > > Is this problem serious enough to justify merging the patch into 3.7? > > > > > And into -stable kernels? > > > > > > > > I wonder if it is a good idea to merge such change at the end of current > > > > -rc period. > > > > > > I'm not sure what you mean by this. > > > > > > But what we do sometimes if we think a patch needs a bit more > > > real-world testing before backporting is to merge it into -rc1 in the > > > normal merge window, and tag it for -stable backporting. That way it > > > gets a few weeks(?) testing in mainline before getting backported. > > > > I just wondered that if it gets merged to v3.7-rc7 there won't be much time > > for real-world testing before final v3.7 release. This patch is in > > linux-next for over a week and I'm not aware of any issues, but -rc releases > > gets much more attention and testing than linux-next tree. > > > > If You think it's fine to put such change to v3.7-rc7 I will send a pull > > request and tag it for stable asap. > > What I'm suggesting is that it be merged for 3.8-rc1 with a -stable > tag, then it will be backported into 3.7.x later on. OK, I will push it to v3.8-rc1 then and tag for stable. Best regards -- Marek Szyprowski Samsung Poland R&D Center -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists