From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jack Steiner Date: Thu, 04 Nov 2004 19:36:29 +0000 Subject: Re: Externalize SLIT table Message-Id: <20041104193629.GA22887@sgi.com> List-Id: References: <20041103205655.GA5084@sgi.com> <20041104.105908.18574694.t-kochi@bq.jp.nec.com> <20041104141337.GA18445@sgi.com> <200411041631.42627.efocht@hpce.nec.com> <20041104170435.GA19687@wotan.suse.de> In-Reply-To: <20041104170435.GA19687@wotan.suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Andi Kleen Cc: Erich Focht , Takayoshi Kochi , linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org On Thu, Nov 04, 2004 at 06:04:35PM +0100, Andi Kleen wrote: > On Thu, Nov 04, 2004 at 04:31:42PM +0100, Erich Focht wrote: > > On Thursday 04 November 2004 15:13, Jack Steiner wrote: > > > I think it would also be useful to have a similar cpu-to-cpu distance > > > metric: > > > ????????% cat /sys/devices/system/cpu/cpu0/distance > > > ????????10 20 40 60 > > > > > > This gives the same information but is cpu-centric rather than > > > node centric. > > > > I don't see the use of that once you have some way to find the logical > > CPU to node number mapping. The "node distances" are meant to be > > I think he wants it just to have a more convenient interface, > which is not necessarily a bad thing. But then one could put the > convenience into libnuma anyways. > > -Andi Yes, strictly convenience. Most of the cases that I have seen deal with cpu placement & cpu distances from each other. I agree that cpu-to-cpu distances can be determined by converting to nodes & finding the node-to-node distance. A second reason is symmetry. If there is a /sys/devices/system/node/node0/distance metric, it seems as though there should also be a /sys/devices/system/cpu/cpu0/distance metric. -- Thanks Jack Steiner (steiner@sgi.com) 651-683-5302 Principal Engineer SGI - Silicon Graphics, Inc.