On 03/06/12 13:59, Stefan Hajnoczi wrote:
On Mon, Mar 5, 2012 at 4:44 PM, Martin Mailand<martin@xxxxxxxxxxxx> 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.
Me too, I would be interested in seeing 0.14.1 being tested with
performance governor so to compare it to master with performance
governor, to make sure that this is not a regression.
BTW, I'll take the opportunity to say that 15.8 or 20.3 k IOPS are very
low figures compared to what I'd instinctively expect from a
paravirtualized block driver.
There are now PCIe SSD cards that do 240 k IOPS (e.g. "OCZ RevoDrive 3
x2 max iops") which is 12-15 times higher, for something that has to go
through a real driver and a real PCI-express bus, and can't use
zero-copy techniques.
The IOPS we can give to a VM is currently less than half that of a
single SSD SATA drive (60 k IOPS or so, these days).
That's why I consider this topic of virtio-blk performances very
important. I hope there can be improvements in this sector...
Thanks for your time
R.
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