Re: qemu-kvm-0.13.0 - winsows 2008 - chkdisk too slow

Avi Kivity
2011-01-06T10:19:27Z

On 01/06/2011 11:42 AM, Nikola Ciprich wrote:
> > - run trace-cmd record -e kvm -b 100000 -P pid1 -P pid2, ctrl-C after a
> seems like it's not possible to specify multiple pids, so

Did you get 'overrun: something' reports from trace-cmd, where something
!= 0?

If you're not sure, please run the trace again. Also try adding '-r 10'
to the command line.

> I've run 4 commands in parallel. Also I can't get monitor information
> since vm is started using libvirt, so I've just used all machine's qemu-kvm
> pids..

Dan, is there a way to hijack the monitor so we can run some commands on
it? Things like 'info registers' and disassembly.

> hope it's OK
> here's the trace:
> http://nelide.cz/downloads/nik/trace.tar.bz2
> n.
>

Looks like vcpu 1 is spinning; perhaps that's normal. If you get hold
of the monitor, please disassemble around 0xfffff80001575d59.

vcpu 0 is busy writing to vga (can you confirm)? looks like bank
switching is hitting synchronize_srcu_expedited(), which is known slow.
Unfortunately that only gets better in 2.6.38.

You can try applying
http://git.kernel.org/?p=linux/kernel/git/sfr/linux-next.git;a=commit;h=46fdb0937f26124700fc9fc80da4776330cc00d3
and see if it helps.

--
error compiling committee.c: too many arguments to function