Avi Kivity schrieb:
On 05/19/2010 11:02 PM, Udo Lembke wrote:Unrelated, what are your smp issues?If i use one cpu i got a good io-performance:e.g. over 500MB/s at the profile "install" of the io-benchmark h2benchw.exe. ( aio=threads | SAS-Raid-0 | ftp://ftp.heise.de/pub/ct/ctsi/h2benchw.zip | hwbenchw.exe -p -w iotest 0)The same test but with two cpus gives results between 27 and 298 MB/s!Also in real life it's noticeable not only with an benchmark. I use a win-vm with two cpu for postscript-ripping and have a performance drop due to the bad io.
Hi,
in the test described before i used virtio, but the same happens with ide (but of course slightly different values).What's your block device model? virtio or ide?
On the guest it's looks like the io-process flap between the cpus. Windows show both cpus together are around 65% (less or more) , but if one CPU-usage rise, the other drop.What does cpu usage look like on guest or host?
On the host: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 5386 root 20 0 1160m 1.0g 1552 R 109 13.5 1:23.58 kvm The guest is a win-xp, but the same happens in real life on a win2003. Udo
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