Re: [libvirt] [PATCH] Canonicalize qemu machine types
On Thu, 2009-07-23 at 13:56 -0400, Cole Robinson wrote:
On 07/23/2009 01:34 PM, Mark McLoughlin wrote:
> Hey,
> Here's a series of patches to implement danpb's suggestion of
> using 'qemu -M ?' to probe for valid machine types and then to build
> on that for the machine type canonicalization.
>
> Cheers,
> Mark.
>
What's the speed difference of GetCapabilities after these patches? Not
that it needs to be fast, but it would be useful to know if it's
slowwwwwwww.
It's a fair point, especially since it wasn't long ago we discussed
this:
http://www.redhat.com/archives/libvir-list/2009-April/msg00537.html
I took your little script, made it do 100 iterations, ran that 20 times
on F-11 and averaged the results:
- Before this series of patches, it's averaging at 10ms, giving 100us
per call
- After this series with only qemu-system-x86 installed, it's
averaging at 1.7s, giving 17ms per call
- With qemu-system-arm/mips/ppc/sparc and xenner installed, it's
averaging at 5.8s, giving 58ms per call
60ms vs 100us is a huge slowdown, relatively speaking. Is 60ms an
unacceptable worst-case got a GetCapabilities call? Probably not, but it
is certainly approaching unacceptable.
Cheers,
Mark.