[PATCH V7 0/2] Improve virtio-blk performance

[Asias He <asias@redhat.com>]

Hi, all

Changes in v7:
- Using vbr->flags to trace request type
- Dropped unnecessary struct virtio_blk *vblk parameter
- Reuse struct virtblk_req in bio done function
- Added performance data on normal SATA device and the reason why make it optional

Fio test shows bio-based IO path gives the following performance improvement:

1) Ramdisk device
     With bio-based IO path, sequential read/write, random read/write
     IOPS boost         : 28%, 24%, 21%, 16%
     Latency improvement: 32%, 17%, 21%, 16%
2) Fusion IO device
     With bio-based IO path, sequential read/write, random read/write
     IOPS boost         : 11%, 11%, 13%, 10%
     Latency improvement: 10%, 10%, 12%, 10%
3) Normal SATA device
     With bio-based IO path, sequential read/write, random read/write
     IOPS boost         : -10%, -10%, 4.4%, 0.5%
     Latency improvement: -12%, -15%, 2.5%, 0.8%

Asias He (2):
  virtio-blk: Add bio-based IO path for virtio-blk
  virtio-blk: Add REQ_FLUSH and REQ_FUA support to bio path

 drivers/block/virtio_blk.c | 301 +++++++++++++++++++++++++++++++++++++++------
 1 file changed, 264 insertions(+), 37 deletions(-)

-- 
1.7.11.2