On Tue, Aug 28, 2012 at 01:54:12PM +0200, Paolo Bonzini wrote: > Hi all, > > this series adds multiqueue support to the virtio-scsi driver, based > on Jason Wang's work on virtio-net. It uses a simple queue steering > algorithm that expects one queue per CPU. LUNs in the same target always > use the same queue (so that commands are not reordered); queue switching > occurs when the request being queued is the only one for the target. > Also based on Jason's patches, the virtqueue affinity is set so that > each CPU is associated to one virtqueue. Is there a spec patch? I did not see one. > I tested the patches with fio, using up to 32 virtio-scsi disks backed > by tmpfs on the host, and 1 LUN per target. > > FIO configuration > ----------------- > [global] > rw=read > bsrange=4k-64k > ioengine=libaio > direct=1 > iodepth=4 > loops=20 > > overall bandwidth (MB/s) > ----------------- > > # of targets single-queue multi-queue, 4 VCPUs multi-queue, 8 VCPUs > 1 540 626 599 > 2 795 965 925 > 4 997 1376 1500 > 8 1136 2130 2060 > 16 1440 2269 2474 > 24 1408 2179 2436 > 32 1515 1978 2319 > > (These numbers for single-queue are with 4 VCPUs, but the impact of adding > more VCPUs is very limited). > > avg bandwidth per LUN (MB/s) > --------------------- > > # of targets single-queue multi-queue, 4 VCPUs multi-queue, 8 VCPUs > 1 540 626 599 > 2 397 482 462 > 4 249 344 375 > 8 142 266 257 > 16 90 141 154 > 24 58 90 101 > 32 47 61 72 > > Testing this may require an irqbalance daemon that is built from git, > due to http://code.google.com/p/irqbalance/issues/detail?id=37. > Alternatively you can just set the affinity manually in /proc. > > Rusty, can you please give your Acked-by to the first two patches? > > Jason Wang (2): > virtio-ring: move queue_index to vring_virtqueue > virtio: introduce an API to set affinity for a virtqueue > > Paolo Bonzini (3): > virtio-scsi: allocate target pointers in a separate memory block > virtio-scsi: pass struct virtio_scsi to virtqueue completion function > virtio-scsi: introduce multiqueue support > > drivers/lguest/lguest_device.c | 1 + > drivers/remoteproc/remoteproc_virtio.c | 1 + > drivers/s390/kvm/kvm_virtio.c | 1 + > drivers/scsi/virtio_scsi.c | 200 ++++++++++++++++++++++++-------- > drivers/virtio/virtio_mmio.c | 11 +- > drivers/virtio/virtio_pci.c | 58 ++++++++- > drivers/virtio/virtio_ring.c | 17 +++ > include/linux/virtio.h | 4 + > include/linux/virtio_config.h | 21 ++++ > 9 files changed, 253 insertions(+), 61 deletions(-) > > _______________________________________________ > Virtualization mailing list > Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx > https://lists.linuxfoundation.org/mailman/listinfo/virtualization -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
