* Richard W.M. Jones <rjones(a)redhat.com> [2007-09-28 11:20]:
beth kon wrote:
>Richard W.M. Jones wrote:
>
>>My results are a bit inconclusive. I have a machine here which
>>supposedly supports NUMA (2 socket, 2 core AMD with hypertransport and
>>two separate banks of RAM).
>>
>>BIOS is _not_ configured to interleave memory. Other BIOS settings
>>lead me to suppose that NUMA is enabled (or at least not disabled).
>>
>>Booting with Daniel's Xen & kernel does not give any messages about
>>NUMA enabled or disabled. (See attached messages).
>>
>># numactl --show
>>physcpubind: 0 1 2 3
>>No NUMA support available on this system.
>>
>Are you setting "numa=on dom0_mem=512m" on the kernel line in grub? I'm
>not sure if the dom0_mem=512m should be required but we were having
>problems when trying to boot numa without it.
Aha, the results are quite a bit better now :-)
virsh shows the correct topology:
<topology>
<cells num='2'>
<cell id='0'>
<cpus num='2'>
<cpu id='0'/>
<cpu id='1'/>
</cpus>
</cell>
<cell id='1'>
<cpus num='2'>
<cpu id='2'/>
<cpu id='3'/>
</cpus>
</cell>
</cells>
</topology>
numactl --show still doesn't work (missing support in dom0 kernel or is
this just completely incompatible with Xen?)
Currently Xen doesn't export any per-domain topology (say a virtual SRAT
table), nor the entire system topology; the goal of the current Xen NUMA
code is to ensure that domains have local resources within a numa-node.
'virsh freecell 0' and 'virsh freecell 1' show numbers which are
plausible (I have no idea if they're actually correct though).
Can I pin a domain or vCPU to memory to see if that works?
Rich.
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