Re: [Qemu-devel] Xenoppix (KNOPPIX5.1.1 + Xen3.0.4 + QEMU/KVM + HTTP-FUSE) is released

[Jens Axboe]

On Fri, Feb 09 2007, Fabrice Bellard wrote:
> Kuniyasu Suzaki wrote:
> > [...]
> > >>2) For best performances with kqemu, it is better to use Linux 2.4 as 
> > >>guest OS (I know this is far from acceptable, but it can help some 
> > >>people to get better performance !).
> >
> >Please tell me the reason why Linux 2.4 shows better performance, if
> >you have time. Does the difference of clock tick cause the problem?
> 
> The Linux 2.6 kernel has more code running with the interrupts disabled 
> than the 2.4 one. kqemu interprets the x86 code when the interrupts are 
> disabled, so it is very slow in this case.
> 
> A potential solution I am investigating is to use the new 
> paravirtualization API of the kernel versions >= 2.6.20.

That'd be a great idea!

-- 
Jens Axboe