From mboxrd@z Thu Jan  1 00:00:00 1970
From: George Dunlap <george.dunlap@eu.citrix.com>
Subject: Re: [PATCH 0/2] Credit2: fix per-socket runqueue setup
Date: Mon, 1 Sep 2014 14:59:23 +0100
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To: Jan Beulich <JBeulich@suse.com>, Dario Faggioli <dario.faggioli@citrix.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>, keir@xen.org, xen-devel <xen-devel@lists.xenproject.org>
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On 08/25/2014 09:31 AM, Jan Beulich wrote:
>>>> On 22.08.14 at 19:15, <dario.faggioli@citrix.com> wrote:
>> root@tg03:~# xl dmesg |grep -i runqueue
>> (XEN) Adding cpu 0 to runqueue 1
>> (XEN)  First cpu on runqueue, activating
>> (XEN) Adding cpu 1 to runqueue 1
>> (XEN) Adding cpu 2 to runqueue 1
>> (XEN) Adding cpu 3 to runqueue 1
>> (XEN) Adding cpu 4 to runqueue 1
>> (XEN) Adding cpu 5 to runqueue 1
>> (XEN) Adding cpu 6 to runqueue 1
>> (XEN) Adding cpu 7 to runqueue 1
>> (XEN) Adding cpu 8 to runqueue 1
>> (XEN) Adding cpu 9 to runqueue 1
>> (XEN) Adding cpu 10 to runqueue 1
>> (XEN) Adding cpu 11 to runqueue 1
>> (XEN) Adding cpu 12 to runqueue 0
>> (XEN)  First cpu on runqueue, activating
>> (XEN) Adding cpu 13 to runqueue 0
>> (XEN) Adding cpu 14 to runqueue 0
>> (XEN) Adding cpu 15 to runqueue 0
>> (XEN) Adding cpu 16 to runqueue 0
>> (XEN) Adding cpu 17 to runqueue 0
>> (XEN) Adding cpu 18 to runqueue 0
>> (XEN) Adding cpu 19 to runqueue 0
>> (XEN) Adding cpu 20 to runqueue 0
>> (XEN) Adding cpu 21 to runqueue 0
>> (XEN) Adding cpu 22 to runqueue 0
>> (XEN) Adding cpu 23 to runqueue 0
>>
>> Which makes a lot more sense. :-)
> But it looks suspicious that the low numbered CPUs get assigned to
> runqueue 1. Is there an explanation for this, or are surprises to be
> expected on larger than dual-socket systems?

Well the explanation is most likely from the cpu_topology info from the 
cover letter (0/2): On his machine, cpus 0-11 are on socket 1, and cpus 
12-23 are on socket 0.  Why that's the topology reported (I presume in 
ACPI?) I'm not sure.

  -George