On Mon, Jun 29, 2020 at 11:28:41AM -0400, Michael S. Tsirkin wrote:

On Mon, Jun 29, 2020 at 10:26:46AM +0100, Stefan Hajnoczi wrote:

quoted

On Sun, Jun 28, 2020 at 02:34:37PM +0800, Jason Wang wrote:

quoted

On 2020/6/25 下午9:57, Stefan Hajnoczi wrote:

quoted

These patches are not ready to be merged because I was unable to measure a
performance improvement. I'm publishing them so they are archived in case
someone picks up this work again in the future.

The goal of these patches is to allocate virtqueues and driver state from the
device's NUMA node for optimal memory access latency. Only guests with a vNUMA
topology and virtio devices spread across vNUMA nodes benefit from this.  In
other cases the memory placement is fine and we don't need to take NUMA into
account inside the guest.

These patches could be extended to virtio_net.ko and other devices in the
future. I only tested virtio_blk.ko.

The benchmark configuration was designed to trigger worst-case NUMA placement:
  * Physical NVMe storage controller on host NUMA node 0

It's possible that numa is not such a big deal for NVMe.
And it's possible that bios misconfigures ACPI reporting NUMA placement
incorrectly.
I think that the best thing to try is to use a ramdisk
on a specific numa node.

Using ramdisk is an interesting idea, thanks.

Stefan