Re: 2 physical-cpu (like 2x6core) config and NUMA?

From: Jike Song
Date: Tue Sep 18 2012 - 02:55:36 EST


On Tue, Sep 18, 2012 at 2:00 AM, Linda Walsh <lkml@xxxxxxxxx> wrote:
> Does the kernel support scheduling based on the different speed of
> memory between "on die" vs. "off die"? I was surprised to see
> that it viewed my system as 1 NUMA node with all 12 on 1 node -- when
> I know that it is physically organized as 2x6.
> Do I have to configure that manually or did I maybe turn off something
> in my kernel config I should have turned on?

Do you have anything printed with:

# acpidump -a --table SRAT

?

I have a Dell box with 2 physical CPUs, each of them has 6 cores. If
I enable "Node Interleaving" in BIOS' Memory Setting, and boot the
kernel, the SRAT table will be invisible to Linux - results the same
topology as you got. If I disable "Node Interleaving" and boot the
kernel, SRAT is present, and the topology is correct.

Hope that helps.

--
Thanks,
Jike
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