On Sun, Nov 4, 2018 at 10:00 PM Jason Wang <jasowang@xxxxxxxxxx> wrote: > > # fio num-jobs > > # A: bare metal over block > > # B: bare metal over file > > # C: virtio-blk over block > > # D: virtio-blk over file > > # E: vhost-blk bio over block > > # F: vhost-blk kiocb over block > > # G: vhost-blk kiocb over file > > # > > # A B C D E F G > > 16 1480k 1506k 101k 102k 1346k 1202k 566k > Hi: > > Thanks for the patches. > > This is not the first attempt for having vhost-blk: > > - Badari's version: https://lwn.net/Articles/379864/ > > - Asias' version: https://lwn.net/Articles/519880/ > > It's better to describe the differences (kiocb vs bio? performance?). > E.g if my memory is correct, Asias said it doesn't give much improvement > compared with userspace qemu. > > And what's more important, I believe we tend to use virtio-scsi nowdays. > So what's the advantages of vhost-blk over vhost-scsi? Hi, Yes, I saw both. Frankly, my implementation is not that different, because the whole thing has only twice more LOC that vhost/test.c. I posted my numbers (see in quoted text above the 16 queues case), IOPS goes from ~100k to 1.2M and almost reaches the physical limitation of the backend. submit_bio() is a bit faster, but can't be used for disk images placed on a file system. I have that submit_bio implementation too. Storage industry is shifting away from SCSI, which has a scaling problem. I can compare vhost-scsi vs vhost-blk if you are curious. Thanks! -- wbr, Vitaly
