From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755864Ab1CKPyw (ORCPT ); Fri, 11 Mar 2011 10:54:52 -0500 Received: from mail-fx0-f46.google.com ([209.85.161.46]:48246 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754736Ab1CKPyv (ORCPT ); Fri, 11 Mar 2011 10:54:51 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=rSP+RoBzt3bnqS32ztO3uMigSY80aNyZ8+A/YglgpmqyqO9MFb3HannbGykf87Mis0 7xCq4R+VJ2SovbDmaGWXJgIlxRRijDuyc+003pUrhpmshxSGcVPPwtuLtanUt4NTERCT 8lJy/U45saaAIqsVtBibzuQ2m9SYEtEem8WhI= Date: Fri, 11 Mar 2011 16:54:46 +0100 From: Tejun Heo To: Yinghai Lu Cc: David Rientjes , Ingo Molnar , tglx@linutronix.de, "H. Peter Anvin" , linux-kernel@vger.kernel.org Subject: Re: [PATCH x86/mm UPDATED] x86-64, NUMA: Fix distance table handling Message-ID: <20110311155446.GH13038@htj.dyndns.org> References: <4D6E9541.2040201@kernel.org> <20110302191338.GE28266@mtj.dyndns.org> <4D6EA975.8070200@kernel.org> <20110302205704.GF28266@mtj.dyndns.org> <4D6EB335.8000306@kernel.org> <20110303061711.GG28266@mtj.dyndns.org> <4D791C9F.1010500@kernel.org> <20110311082938.GC13038@htj.dyndns.org> <20110311083351.GD13038@htj.dyndns.org> <4D7A4430.1030301@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4D7A4430.1030301@kernel.org> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 11, 2011 at 07:48:00AM -0800, Yinghai Lu wrote: > On 03/11/2011 12:33 AM, Tejun Heo wrote: > > On Fri, Mar 11, 2011 at 09:29:38AM +0100, Tejun Heo wrote: > >> Also, I don't think your patch is correct. Even if there is phys_dist > > ^ > > no > >> table, emu distance tables should be built because emulated nids don't > >> map to physical nids one to one. ie. Two different emulated nids can > >> share a physical node and the distance table should explicitly reflect > >> that. > > ok, when original SLIT is not there, mean only one really node. > so the new distance table should be filled with LOCAL_DISTANCE. No, NUMA implementation can skip numa_set_distance() entirely if the distance is LOCAL_DISTANCE if nids are equal, REMOTE_DISTANCE otherwise. In fact, any amdtopology configuraiton would behave this way, so it's incorrect to fill the table with LOCAL_DISTANCE. You have to check the physnid mapping and build new table whether physical table exists or not. Lack of physical distance table doesn't mean all nodes are LOCAL_DISTANCE. -- tejun