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: Tue, 11 May 2010 09:52:28 -0700 From: Dmitry Torokhov <dmitry.torokhov@...il.com> To: Pekka Enberg <penberg@...helsinki.fi> Cc: Mike Frysinger <vapier.adi@...il.com>, Andrew Morton <akpm@...ux-foundation.org>, Oskar Schirmer <os@...ix.com>, Michael Hennerich <Michael.Hennerich@...log.com>, linux-input@...r.kernel.org, linux-kernel@...r.kernel.org, Daniel Glöckner <dg@...ix.com>, Oliver Schneidewind <osw@...ix.com>, Johannes Weiner <jw@...ix.com>, Christoph Lameter <cl@...ux-foundation.org>, Nick Piggin <npiggin@...e.de>, David Rientjes <rientjes@...gle.com>, Matt Mackall <mpm@...enic.com> Subject: Re: [PATCH v3] ad7877: keep dma rx buffers in seperate cache lines On Tue, May 11, 2010 at 09:42:03AM +0300, Pekka Enberg wrote: > Hi Dmitry, > > On Tue, May 11, 2010 at 9:33 AM, Dmitry Torokhov > <dmitry.torokhov@...il.com> wrote: > >> what guarantee exactly do you have for that statement ? > > > > The data is kmalloced, kmalloc aligns on cacheline boundary AFAIK which > > means that next kmalloc data chunk will not share "our" cacheline. > > No, there are no such guarantees. kmalloc() aligns on > ARCH_KMALLOC_MINALIGN or ARCH_SLAB_MINALIGN depending on which is > bigger but beyond that, there are no guarantees. You can, of course, > use kmem_cache_create() with SLAB_HWCACHE_ALIGN to align on cacheline > boundary. > The architectures that we are trying to deal with here should be forcing kmalloc to the cache boundary already though - otherwise they would not be able to used kmalloced memory for DMA buffers at all. Or am I utterly lost here? -- Dmitry -- 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