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| author | Stefan Hajnoczi | 2015-07-20 17:54:16 +0200 |
|---|---|---|
| committer | Stefan Hajnoczi | 2015-10-12 10:21:10 +0200 |
| commit | fc73548e444ae3239f6cef44a5200b5d2c3e85d1 (patch) | |
| tree | b403ecd4b4a52f4b10999d36fb78cddf5ff91a0a /include/exec/user | |
| parent | sdhci: Pass drive parameter to sdhci-pci via qdev property (diff) | |
| download | qemu-fc73548e444ae3239f6cef44a5200b5d2c3e85d1.tar.gz qemu-fc73548e444ae3239f6cef44a5200b5d2c3e85d1.tar.xz qemu-fc73548e444ae3239f6cef44a5200b5d2c3e85d1.zip | |
virtio-blk: use blk_io_plug/unplug for Linux AIO batching
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 <psuriset@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Diffstat (limited to 'include/exec/user')
0 files changed, 0 insertions, 0 deletions