lkml.org 
[lkml]   [2016]   [Mar]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 2/3] x86/topology: Fix AMD core count
From
Date
On 03/21/2016 08:57 AM, Borislav Petkov wrote:
> +- AMD: the number of cores in a processor. On a system where cores are
> +clustered in groups of 2, 4 or more in compute units, this variable
> +denotes the number of*compute units* on the node.
> +
> +In both cases, the number of scheduling threads is computed by doing:
> +
> + x86_max_cores * smp_num_siblings
> +
> +This means:
> +
> +* smp_num_siblings: the number of siblings in a core. On AMD with
> +compute units, this number is the number of compute unit siblings,
> +i.e., compute unit cores in a single compute unit, according to their
> +nomenclature.
> -- hr
Boris, this documentation will help tremendously. In just this line of
code:

nr_local_cpus = nr_cores * nr_siblings

we have an Intel HT = AMD core = logical_cpu
and core = AMD compute unit.

Anybody surprised there was a bug?

The surprising thing is that running lscpu on a 32 core 2 socket 6300
Opteron system without
the patches I get the same output as with the patches and it matches
Ray's. I don't see an impact.

\
 
 \ /
  Last update: 2016-03-22 09:41    [W:0.093 / U:0.028 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site