Re: [Xen-devel] gross qemu behavior

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 04.04.14 at 11:34, <pbonzini@xxxxxxxxxx> wrote:
> Il 04/04/2014 08:45, Jan Beulich ha scritto:
>> Very odd, but fitting the picture of trying to be as slow
>> as possible (in the context of the breakage introduced by
>> ef437690 "x86/HVM: correct CPUID leaf 80000008 handling" I

(For the record - I was off by a line when copy-and-pasting this,
it really was 8bad6c56 "x86/HVM: fix preemption handling in
do_hvm_op()").

>> had to run qemu-traditional and qemu-upstream, and the
>> performance of the guest visibly _much_ better with the former,
>> which I consider rather worrying).
> 
> That's quite unexpected.  What was your configuration and workload?  And 
> what was slower exactly?  Disk, network or video (as an initial 
> simplification).

Video in particular. Disk and network, using PV drivers, obviously are
pretty independent on qemu version (and don't matter much during
early boot). But even normal execution during early BIOS initialization
seems notably slower (under the assumption that when nothing
changes on the virtual screen, video performance doesn't matter).
But of course that's not comparing apples to apples, as the two
BIOSes also differ...

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel