Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755326AbZCQTpQ (ORCPT ); Tue, 17 Mar 2009 15:45:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753564AbZCQTpD (ORCPT ); Tue, 17 Mar 2009 15:45:03 -0400 Received: from smtp.ultrahosting.com ([74.213.174.254]:53681 "EHLO smtp.ultrahosting.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753848AbZCQTpA (ORCPT ); Tue, 17 Mar 2009 15:45:00 -0400 Date: Tue, 17 Mar 2009 15:41:53 -0400 (EDT) From: Christoph Lameter X-X-Sender: cl@qirst.com To: David Rientjes cc: Andrew Morton , Pekka Enberg , Matt Mackall , Paul Menage , Randy Dunlap , KOSAKI Motohiro , linux-kernel@vger.kernel.org Subject: Re: [patch -mm v2] cpusets: add memory_slab_hardwall fla In-Reply-To: Message-ID: References: User-Agent: Alpine 1.10 (DEB 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1312 Lines: 38 On Mon, 16 Mar 2009, David Rientjes wrote: > Here is my example (for the third time) if, for example, mems are grouped > by the cpus for which they have affinity: Well I wish I had been send the messages the first two times. > /dev/cpuset > --> cpuset_A (cpus 0-1, mems 0-3) > --> cpuset_B (cpus 2-3, mems 4-7) > --> cpuset_C (cpus 4-5, mems 8-11) > --> ... A cpu can only be assigned to a single numa node. cpuset_A/B/C have 2 cpus but 4 nodes. What is the mapping of nodes to cpus? > Within that, we isolate mems for specific jobs: > > /dev/cpuset > --> cpuset_A (cpus 0-1, mems 0-3) > --> job_1 (mem 0) > --> job_2 (mem 1-2) > --> job_3 (mem 3) > --> ... Nobody would do that since usually multiple cpus are associated with a single node. Memory and processors are assigned together in order to reduce latencies. Randomly assigning processors to nodes will cause latencies and significant traffic on the interconnect. This does not look sane and would not be optimized in any way. Are these memoryless nodes? What are you trying to accomplish? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/