[Qemu-devel] [PATCH v3 0/2] block: Handle multiple write requests at once

[Kevin Wolf <kwolf@redhat.com>]

virtio often issues multiple requests in a row, but each one independently. If
the block drivers knew all of the requests, they could optimize the way they
handle the requests. See the description of patch 1 for how qcow2 can use this
to avoid unnecessary writes to the disk.

v2:
The simple request merging code isn't qcow2 specific at all. Enable it for all
formats. A cleverer merging policy can later still be implemented in a driver
specific way.

v3:
Handle overlapping requests, add hook for block drivers to merge even more
requests.

Kevin Wolf (2):
  Add bdrv_aio_multiwrite
  virtio-blk: Use bdrv_aio_multiwrite

 block.c         |  183 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 block.h         |   15 +++++
 block_int.h     |    6 ++
 cutils.c        |   25 ++++++++
 hw/virtio-blk.c |   50 +++++++++++++---
 qemu-common.h   |    1 +
 6 files changed, 272 insertions(+), 8 deletions(-)