From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx182.postini.com [74.125.245.182]) by kanga.kvack.org (Postfix) with SMTP id 2D9D26B00FD for ; Mon, 19 Mar 2012 16:03:28 -0400 (EDT) Message-ID: <1332187387.18960.389.camel@twins> Subject: Re: [RFC][PATCH 00/26] sched/numa From: Peter Zijlstra Date: Mon, 19 Mar 2012 21:03:07 +0100 In-Reply-To: <4F672384.1030601@redhat.com> References: <20120316144028.036474157@chello.nl> <4F670325.7080700@redhat.com> <1332155527.18960.292.camel@twins> <4F671B90.3010209@redhat.com> <1332158992.18960.316.camel@twins> <4F672384.1030601@redhat.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: Avi Kivity Cc: Linus Torvalds , Andrew Morton , Thomas Gleixner , Ingo Molnar , Paul Turner , Suresh Siddha , Mike Galbraith , "Paul E. McKenney" , Lai Jiangshan , Dan Smith , Bharata B Rao , Lee Schermerhorn , Andrea Arcangeli , Rik van Riel , Johannes Weiner , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Mon, 2012-03-19 at 14:16 +0200, Avi Kivity wrote: > > Afaik we do not use dma engines for memory migration.=20 >=20 > We don't, but I think we should.=20 ISTR we (the community) had this discussion once. I also seem to remember the general consensus being that DMA engines would mostly likely not be worth the effort, although I can't really recall the specifics. Esp. for 4k pages the setup of the offload will likely be more expensive than actually doing the memcpy. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org