On 11/05/2018 04:00 AM, Jason Wang wrote: > > On 2018/11/3 上午2:21, Vitaly Mayatskikh wrote: >> vhost_blk is a host-side kernel mode accelerator for virtio-blk. The >> driver allows VM to reach a near bare-metal disk performance. See IOPS >> numbers below (fio --rw=randread --bs=4k). >> >> This implementation uses kiocb interface. It is slightly slower than >> going directly through bio, but is simpler and also works with disk >> images placed on a file system. >> >> # 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 >> >> 1 171k 151k 148k 151k 195k 187k 175k >> 2 328k 302k 249k 241k 349k 334k 296k >> 3 479k 437k 179k 174k 501k 464k 404k >> 4 622k 568k 143k 183k 620k 580k 492k >> 5 755k 697k 136k 128k 737k 693k 579k >> 6 887k 808k 131k 120k 830k 782k 640k >> 7 1004k 926k 126k 131k 926k 863k 693k >> 8 1099k 1015k 117k 115k 1001k 931k 712k >> 9 1194k 1119k 115k 111k 1055k 991k 711k >> 10 1278k 1207k 109k 114k 1130k 1046k 695k >> 11 1345k 1280k 110k 108k 1119k 1091k 663k >> 12 1411k 1356k 104k 106k 1201k 1142k 629k >> 13 1466k 1423k 106k 106k 1260k 1170k 607k >> 14 1517k 1486k 103k 106k 1296k 1179k 589k >> 15 1552k 1543k 102k 102k 1322k 1191k 571k >> 16 1480k 1506k 101k 102k 1346k 1202k 566k >> >> Vitaly Mayatskikh (1): >> Add vhost_blk driver >> >> drivers/vhost/Kconfig | 13 ++ >> drivers/vhost/Makefile | 3 + >> drivers/vhost/blk.c | 510 +++++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 526 insertions(+) >> create mode 100644 drivers/vhost/blk.c >> > > 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? For the record, we still do use virtio-blk a lot. As we see new things like discard/write zero support it seems that others do as well.
