Hi,
The commit 580b6b2aa2(dataplane: use the QEMU block layer for I/O)
introduces ~40% throughput regression on virtio-blk dataplane, and
one of causes is that submitting I/O as a batch is removed.
This patchset trys to introduce this mechanism on block, at least,
linux-aio can benefit from that.
With these patches, it is observed that thoughout on virtio-blk
dataplane can be improved a lot, see data in commit log of patch
3/3.
It should be possible to apply the batch mechanism to other devices
(such as virtio-scsi) too.
TODO:
- support queuing I/O to multi files which need lots of change
to linux-aio for scsi devies
V4:
- support other non-raw formats with under-optimized performance
- use reference counter for plug & unplug
- flush io queue before sending flush command
V3:
- only support submitting I/O as a batch for raw format, pointed by
Kevin
V2:
- define return value of bdrv_io_unplug as void, suggested by Paolo
- avoid busy-wait for handling io_submit
V1:
- move queuing io stuff into linux-aio.c as suggested by Paolo
Thanks,
--
Ming Lei
