[Qemu-devel] [PATCH v3 0/3] linux-aio: introduce submit I/O at batch

[Ming Lei]

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 at 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.

V3:
        - only support submitting I/O at 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