Hi Paolo,
I am not sure if the following information is clear:
I have run a guest on qemu 2.3.0 within different kernels (linux-2.6.32 and higher versions) on the same PC and tested the FTP performance of the guest (the server is a windows OS on a remote PC). I found that the FTP download throughput degraded significantly from 2.6.39 or later version but the upload performance only vary slightly. The qemu command line is as following:
kvm -hda XX.img -net ... -smp 4 m 2G -enable-kvm.
And I have tried to enabled the Linux AIO support for QEMU but also got nothing improved. I have also changed the smp/hda/memory configuration but got no luck. The problem might exist in the linux kernel itself. Could you please point some suspicious functions of the qemu to debug this problem?
Thank,
Yi.
At 2015-06-24 20:32:30, "Paolo Bonzini" <address@hidden> wrote:
>
>
>On 24/06/2015 14:31, cauchy-love wrote:
>>
>> Sorry, but I don't know what does bisect mean exactly.Could you
>> please explain it? I feel it might be some kernel configuration items
>> introduce this problem.I am also trying other kernel versions from
>> 2.6.34 to 2.6.38 (2.6.33.3 has good performance like 2.6.32) and will
>> show you the results.
>
>I meant exactly what you are already doing. Thanks!
>
>Paolo
>