Messages in this thread | | | Date | Thu, 6 Aug 2009 18:08:35 +0200 | From | Andreas Herrmann <> | Subject | Re: [PATCH 0/5 v4] x86: Adapt CPU topology detection for AMD Magny-Cours |
| |
On Thu, Aug 06, 2009 at 02:25:19PM +0200, Brice Goglin wrote: > Andreas Herrmann wrote: > > Of course I thought also to implement it this way because it looks > > more consistent, but IMHO the patches are less intrusive if this > > scheme is _not_ used. Instead I kept core_siblings as is ("for > > historic reasons", nobody needs to accustom to new semantics). And use > > cpu_node_siblings where it really matters. > > > > Well, core_siblings and cpu_node_sibling will only be different on > Magny-Cours anyway. So even if core_siblings becomes "all cores in > cpu_node" instead of "all cores in socket", it won't actually break any > existing setup. I personally prefer having the same kind of semantics > for all foo_siblings rather than having something with a different > meaning between core and thread.
You just want to have the user interface adapted to your semantics. I.e. you want to have following attributes: (from Documentation/cputopology.txt)
1) /sys/devices/system/cpu/cpuX/topology/physical_package_id: represent the physical package id of cpu X; 2) /sys/devices/system/cpu/cpuX/topology/core_id: represent the cpu core id to cpu X; 3) /sys/devices/system/cpu/cpuX/topology/cpu_node_id: represent the processor internal node_id to cpu X; 4) /sys/devices/system/cpu/cpuX/topology/thread_siblings: represent the thread siblings to cpu X in the same core; 5) /sys/devices/system/cpu/cpuX/topology/core_siblings: represent the thread siblings to cpu X in the same processor internal node; 6) /sys/devices/system/cpu/cpuX/topology/cpu_node_siblings: represent the thread siblings to cpu X in the same physical package;
Note: In case of multi-node processors (e.g. Magny-Cours) 5 and 6 differ. For all other CPUs 5 and 6 provide similar values and cpu_node_id is 0.
Ok, I can modify the first two patches accordingly to swap the two attributes and also provide an update for the documentation file.
(But I will keep the internal identifiers for the cpu_node stuff as is.)
Thanks, Andreas
-- Operating | Advanced Micro Devices GmbH System | Karl-Hammerschmidt-Str. 34, 85609 Dornach b. München, Germany Research | Geschäftsführer: Thomas M. McCoy, Giuliano Meroni Center | Sitz: Dornach, Gemeinde Aschheim, Landkreis München (OSRC) | Registergericht München, HRB Nr. 43632
-- 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/
| |