Messages in this thread | | | Date | Tue, 4 Sep 2012 15:48:00 +0300 | From | "Michael S. Tsirkin" <> | Subject | Re: [PATCH 5/5] virtio-scsi: introduce multiqueue support |
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On Tue, Aug 28, 2012 at 01:54:17PM +0200, Paolo Bonzini wrote: > This patch adds queue steering to virtio-scsi. When a target is sent > multiple requests, we always drive them to the same queue so that FIFO > processing order is kept. However, if a target was idle, we can choose > a queue arbitrarily. In this case the queue is chosen according to the > current VCPU, so the driver expects the number of request queues to be > equal to the number of VCPUs. This makes it easy and fast to select > the queue, and also lets the driver optimize the IRQ affinity for the > virtqueues (each virtqueue's affinity is set to the CPU that "owns" > the queue). > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
I guess an alternative is a per-target vq. Is the reason you avoid this that you expect more targets than cpus? If yes this is something you might want to mention in the log.
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