Re: [Qemu-devel] virtio-blk performance regression and qemu-kvm

[Stefan Hajnoczi]

On Mon, Mar 5, 2012 at 4:44 PM, Martin Mailand <address@hidden> wrote:
> Am 05.03.2012 17:35, schrieb Stefan Hajnoczi:
>
>>> 1. Test on i7 Laptop with Cpu governor "ondemand".
>>> >
>>> >  v0.14.1
>>> >  bw=63492KB/s iops=15873
>>> >  bw=63221KB/s iops=15805
>>> >
>>> >  v1.0
>>> >  bw=36696KB/s iops=9173
>>> >  bw=37404KB/s iops=9350
>>> >
>>> >  master
>>> >  bw=36396KB/s iops=9099
>>> >  bw=34182KB/s iops=8545
>>> >
>>> >  Change the Cpu governor to "performance"
>>> >  master
>>> >  bw=81756KB/s iops=20393
>>> >  bw=81453KB/s iops=20257
>>
>> Interesting finding.  Did you show the 0.14.1 results with
>> "performance" governor?
>
>
>
> Hi Stefan,
> all results are with "ondemand" except the one where I changed it to
> "performance"
>
> Do you want a v0.14.1 test with the governor on "performance"?

Yes, the reason why that would be interesting is because it allows us
to put the performance gain with master+"performance" into
perspective.  We could see how much of a change we get.

Does the CPU governor also affect the result when you benchmark with
real disks instead of ramdisk?  I can see how the governor would
affect ramdisk, but would expect real disk I/O to be impacted much
less.

Stefan