Re: [PATCH v2 0/3] Improve virtio-blk performance

[Asias He <asias@redhat.com>]

On 06/18/2012 05:14 PM, Stefan Hajnoczi wrote:
> On Mon, Jun 18, 2012 at 7:53 AM, Asias He <asias@redhat.com> wrote:
>> Fio test shows it gives, 28%, 24%, 21%, 16% IOPS boost and 32%, 17%, 21%, 16%
>> latency improvement for sequential read/write, random read/write respectively.
>
> Sounds great.  What storage configuration did you use (single spinning
> disk, SSD, storage array) and are these numbers for parallel I/O or
> sequential I/O?

I used ramdisk as the backend storage.

> What changed since Minchan worked on this?  I remember he wasn't
> satisfied that this was a clear win.  Your numbers are strong so
> either you fixed something important or you are looking at different
> benchmark configurations.

I am using kvm tool instead qemu. He wasn't satisfied the poor 
sequential performance. I removed the plug and unplug operation and bio 
completion batching. You can grab Michan's patch and make a diff to see 
the details.

Here is the fio's config file.

[global]
exec_prerun="echo 3 > /proc/sys/vm/drop_caches"
group_reporting
norandommap
ioscheduler=noop
thread
bs=512
size=4MB
direct=1
filename=/dev/vdb
numjobs=256
ioengine=aio
iodepth=64
loops=3

[seq-read]
stonewall
rw=read

[seq-write]
stonewall
rw=write

[rnd-read]
stonewall
rw=randread

[rnd-write]
stonewall
rw=randwrite



-- 
Asias