On Wed, Oct 05, 2022 at 12:14:18PM +0300, Andrey Zhadchenko wrote: > On 10/4/22 21:13, Stefan Hajnoczi wrote: > > On Mon, Jul 25, 2022 at 11:55:26PM +0300, Andrey Zhadchenko wrote: > > > Although QEMU virtio-blk is quite fast, there is still some room for > > > improvements. Disk latency can be reduced if we handle virito-blk requests > > > in host kernel so we avoid a lot of syscalls and context switches. > > > > > > The biggest disadvantage of this vhost-blk flavor is raw format. > > > Luckily Kirill Thai proposed device mapper driver for QCOW2 format to > > > attach > > > files as block devices: > > > https://www.spinics.net/lists/kernel/msg4292965.html > > > > > > Also by using kernel modules we can bypass iothread limitation and finaly > > > scale > > > block requests with cpus for high-performance devices. This is planned to > > > be > > > implemented in next version. > > > > Hi Andrey, > > Do you have a new version of this patch series that uses multiple > > threads? > > > > I have been playing with vq-IOThread mapping in QEMU and would like to > > benchmark vhost-blk vs QEMU virtio-blk mq IOThreads: > > https://gitlab.com/stefanha/qemu/-/tree/virtio-blk-mq-iothread-prototype > > > > Thanks, > > Stefan > > Hi Stefan > For now my multi-threaded version is only available for Red Hat 9 5.14.0 > kernel. If you really want you can grab it from here: > https://lists.openvz.org/pipermail/devel/2022-September/079951.html (kernel) > For QEMU part all you need is adding to vhost_blk_start something like: > > #define VHOST_SET_NWORKERS _IOW(VHOST_VIRTIO, 0x1F, int) > ioctl(s->vhostfd, VHOST_SET_NWORKERS, &nworkers); > > Or you can wait a bit. I should be able to send second versions by the end > of the week (Monday in worst case).
Thanks, I will wait for the next revision. Stefan
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