Messages in this thread | | | Date | Tue, 26 Feb 2008 15:31:11 -0800 | From | Ravikiran Thirumalai <> | Subject | Re: [PATCH] x86_64: make amd quad core 8 socket system not be clustered_box v2 |
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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@scalemp.com> 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@scalemp.com> 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.
Kiran
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