On Mon, Jul 20, 2015 at 04:54:16PM +0100, Stefan Hajnoczi wrote: > The raw-posix block driver implements Linux AIO batching so multiple > requests can be submitted with a single io_submit(2) system call. > Batching is currently only used by virtio-scsi and > virtio-blk-data-plane. > > Enable batching for regular virtio-blk so the number of io_submit(2) > system calls is reduced for workloads with queue depth > 1. > > In 4KB random read performance tests with queue depth 32, the CPU > utilization on the host is reduced by 9.4%. The fio job is as follows: > > [global] > bs=4k > ioengine=libaio > iodepth=32 > direct=1 > sync=0 > time_based=1 > runtime=30 > clocksource=gettimeofday > ramp_time=5 > > [job1] > rw=randread > filename=/dev/vdb > size=4096M > write_bw_log=fio > write_iops_log=fio > write_lat_log=fio > log_avg_msec=1000 > > This benchmark was run on an raw image on LVM. The disk was an SSD > drive and -drive cache=none,aio=native was used. > > Tested-by: Pradeep Surisetty <[email protected]> > Signed-off-by: Stefan Hajnoczi <[email protected]> > --- > hw/block/virtio-blk.c | 4 ++++ > 1 file changed, 4 insertions(+)
Thanks, applied to my master tree: https://github.com/stefanha/qemu/commits/master Stefan
