Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756112AbXLHEqF (ORCPT ); Fri, 7 Dec 2007 23:46:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751935AbXLHEpy (ORCPT ); Fri, 7 Dec 2007 23:45:54 -0500 Received: from smtp-out.google.com ([216.239.33.17]:61843 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753345AbXLHEpx (ORCPT ); Fri, 7 Dec 2007 23:45:53 -0500 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=received:date:from:x-x-sender:to:cc:subject:in-reply-to: message-id:references:mime-version:content-type; b=yq0/rS5016/gf05sUGQE2e2HJkv/dYIha69CILnS/yPg3azBssPIp3tvks8KBzldO Jt3yB6DyDedURtWxvyVeQ== Date: Fri, 7 Dec 2007 20:45:21 -0800 (PST) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Balbir Singh cc: linuxppc-dev@ozlabs.org, Nathan Lynch , LKML Subject: Re: [PATCH] Fake NUMA emulation for PowerPC In-Reply-To: <475A1E6E.3010303@linux.vnet.ibm.com> Message-ID: References: <20071207211425.10223.91240.sendpatchset@balbir-laptop> <20071207221106.GH16824@localdomain> <4759C89B.9000709@linux.vnet.ibm.com> <475A1E6E.3010303@linux.vnet.ibm.com> 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: 1151 Lines: 26 On Sat, 8 Dec 2007, Balbir Singh wrote: > > You're going to want to distribute the cpu's based on how they match up > > physically with the actual platform that you're running on. x86_64 does > > Could you explain this better, how does it match up CPU's with fake NUMA > memory? Is there some smartness there? I'll try and look at the code and > also see what I can do for PowerPC > numa_cpumask_lookup_table[] would return the correct cpumask for the fake node index. Then all the code that uses node_to_cpumask() in generic kernel code like the scheduler and VM still preserve their true NUMA affinity that matches the underlying hardware. I tried to make x86_64 fake NUMA as close to the real thing as possible. You also probably want to make all you changes dependent on CONFIG_NUMA_EMU like the x86_64 case. That'll probably be helpful as you extend this tool more and more. David -- 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/