On 08/06/2009 07:35 PM, Christoph Hellwig wrote:
Michael suggested to me a while ago to try MSI with virtio-blk and I played with this small patch:Index: qemu-kvm/hw/virtio-blk.c =================================================================== --- qemu-kvm.orig/hw/virtio-blk.c +++ qemu-kvm/hw/virtio-blk.c @@ -416,6 +416,7 @@ VirtIODevice *virtio_blk_init(DeviceStat s->vdev.get_config = virtio_blk_update_config; s->vdev.get_features = virtio_blk_get_features; s->vdev.reset = virtio_blk_reset; + s->vdev.nvectors = 2; s->bs = bs; s->rq = NULL; if (strlen(ps = (char *)drive_get_serial(bs))) which gave about 5% speedups on 4k sized reads and writes, see the full iozone output I attached. Now getting the information about using multiple MSI vectors from the command line to virtio-blk similar to how virtio-net does seems extremly messy right now. Waiting for Gerd's additional qdev patches to make it easier as a qdev property.
Looks good. Anthony, I think this applies upstream? -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
