Re: [PATCH] x86_64: make amd quad core 8 socket system not be clustered_box v2

From: Yinghai Lu
Date: Tue Feb 26 2008 - 18:41:45 EST


On Tue, Feb 26, 2008 at 3:31 PM, Ravikiran Thirumalai <kiran@xxxxxxxxxxx> wrote:
> On Tue, Feb 26, 2008 at 03:16:16PM -0800, Yinghai Lu wrote:
> >On Tue, Feb 26, 2008 at 1:24 PM, Ravikiran Thirumalai <kiran@xxxxxxxxxxx> wrote:
> >>
> >> On Tue, Feb 26, 2008 at 01:10:57PM -0800, Yinghai Lu wrote:
> >> >On Tue, Feb 26, 2008 at 12:32 PM, Ravikiran Thirumalai
> >> ><kiran@xxxxxxxxxxx> wrote:
> >> >> On Tue, Feb 26, 2008 at 11:00:58AM -0800, Yinghai Lu wrote:
> >> >> >
> >> >> >1. if acpi=off ?
> >> >>
> >> >> Well that is not a realistic scenario for any multi chassi NUMA machine,
> >> >> since the proximity information is very important and turning acpi off
> >> >> deprives the OS of this information.
> >> >
> >> >actually OS should detect the distance instead of rely on SLIT.
> >>
> >> How does it do that? ACPI SRAT is needed to determine this, and it wouldn't
> >> work if acpi=off.
> >
> >srat only have apicid to node mapping, and ram to node mapping.
>
> Which is very important for performance.
>
>
> >
> >for amd64 system, when acpi=off
> >ram to node mapping can be retrieved from pci conf space
>
> I was referring to all types of numa systems, not just AMD. The pci config
> space is amd specific. Multi chassi systems in particular would be
> acpi SRAT based. Anyways.

can you try x86.git#testing your vsmp to see if is_vsmp_box is working?

http://people.redhat.com/mingo/x86.git/README

YH
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