On 06/13/2014 11:29 AM, Ming Lei wrote: > Hi, > > This patches try to support multi virtual queues(multi-vq) in one > virtio-blk device, and maps each virtual queue(vq) to blk-mq's > hardware queue. > > With this approach, both scalability and performance problems on > virtio-blk device get improved. > > For verifying the improvement, I implements virtio-blk multi-vq over > qemu's dataplane feature, and both handling host notification > from each vq and processing host I/O are still kept in the per-device > iothread context, the changes are based on qemu v2.0.0 release, and > can be accessed from below tree: > > git://kernel.ubuntu.com/ming/qemu.git #v2.0.0-virtblk-dataplane-mq > > For enabling the multi-vq feature, 'num_queues=N' need to be added into > '-device virtio-blk-pci ...' of qemu command line, and suggest to pass > 'vectors=N+1' to keep one MSI irq vector per each vq, and the feature > depends on x-data-plane. > > Fio(libaio, randread, iodepth=64, bs=4K, jobs=N) is run inside VM to > verify the improvement. > > I just create a small quadcore VM and run fio inside the VM, and > num_queues of the virtio-blk device is set as 2, but looks the > improvement is still obvious. > > 1), about scalability > - without mutli-vq feature > -- jobs=2, thoughput: 145K iops > -- jobs=4, thoughput: 100K iops > - without mutli-vq feature > -- jobs=2, thoughput: 186K iops > -- jobs=4, thoughput: 199K iops Awesome! I was hoping someone would do that, and make virtio-blk take full advantage of blk-mq. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
