Re: Externalize SLIT table

[Jack Steiner <steiner@sgi.com>]

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.