Re: [libvirt] [PATCH 12/12] nodedev: Export NUMA node locality for PCI devices
On Thu, May 29, 2014 at 10:32:46AM +0200, Michal Privoznik wrote:
A PCI device can be associated with a specific NUMA node. Later,
when
a guest is pinned to one NUMA node the PCI device can be assigned on
different NUMA node. This makes DMA transfers travel across nodes and
thus results in suboptimal performance. We should expose the NUMA node
locality for PCI devices so management applications can make better
decisions.
Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
---
Notes:
All the machines I have tried this on had only -1 in the
numa_node file. From the kernel sources it seems that this is the
default, so I'm not printing the <numa/> element into the XML in
this case. But I'd like to hear your opinion.
Yes, I believe '-1' means that there is no NUMA locality info
available for the device, so it makes sense to skip this.
Regards,
Daniel
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