Re: [PATCH] x86: new topology for multi-NUMA-node CPUs

From: Karel Zak
Date: Fri Sep 19 2014 - 07:46:07 EST


On Thu, Sep 18, 2014 at 12:33:34PM -0700, Dave Hansen wrote:
> The sysfs effects here cause an issue with the hwloc tool where
> it gets confused and thinks there are more sockets than are
> physically present.
>
> Before this patch, there are two packages:
>
> # cd /sys/devices/system/cpu/
> # cat cpu*/topology/physical_package_id | sort | uniq -c
> 18 0
> 18 1
>
> But 4 _sets_ of core siblings:
>
> # cat cpu*/topology/core_siblings_list | sort | uniq -c
> 9 0-8
> 9 18-26
> 9 27-35
> 9 9-17
>
> After this set, there are only 2 sets of core siblings, which
> is what we expect for a 2-socket system.
>
> # cat cpu*/topology/physical_package_id | sort | uniq -c
> 18 0
> 18 1
> # cat cpu*/topology/core_siblings_list | sort | uniq -c
> 18 0-17
> 18 18-35

hmm... it would be also nice to test it with lscpu(1) from
util-linux (but it uses maps rather than lists from cpu*/topology/).

Karel

--
Karel Zak <kzak@xxxxxxxxxx>
http://karelzak.blogspot.com
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