Il 05/07/2012 03:52, Nicholas A. Bellinger ha scritto: > > fio randrw workload | virtio-scsi-raw | virtio-scsi+tcm_vhost | bare-metal raw block > ------------------------------------------------------------------------------------ > 25 Write / 75 Read | ~15K | ~45K | ~70K > 75 Write / 25 Read | ~20K | ~55K | ~60K This is impressive, but I think it's still not enough to justify the inclusion of tcm_vhost. In my opinion, vhost-blk/vhost-scsi are mostly worthwhile as drivers for improvements to QEMU performance. We want to add more fast paths to QEMU that let us move SCSI and virtio processing to separate threads, we have proof of concepts that this can be done, and we can use vhost-blk/vhost-scsi to find bottlenecks more effectively. In fact, virtio-scsi-qemu and virtio-scsi-vhost are effectively two completely different devices that happen to speak the same SCSI transport. Not only virtio-scsi-vhost must be configured outside QEMU and doesn't support -device; it (obviously) presents different inquiry/vpd/mode data than virtio-scsi-qemu, so that it is not possible to migrate one to the other. I don't think vhost-scsi is particularly useful for virtualization, honestly. However, if it is useful for development, testing or benchmarking of lio itself (does this make any sense? :)) that could be by itself a good reason to include it. Paolo _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
