Re: keeping time

["Yang, Sheng" <sheng.yang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>]

On Thursday 27 December 2007 14:51:06 Yves Dorfsman wrote:
> On Thu, 27 Dec 2007, Yang, Sheng wrote:
> > What's your guest kernel version?
>
> 2.6.22
>
> > When I debug my in kernel PIT(not sent yet, though kept for months), I
> > found the kernel version have something to do with the timer accuracy. On
> > my limited test, the kernel 2.6.18, 2.6.20, 2.6.22 with default kernel
> > parameters works well with my PIT patch. But for kernel 2.6.9, I have to
> > use "clock=pit", otherwise the timer is much faster.
>
> I have added clock=pit, but it does not help. Do you need a specific patch
> for this, or do all kernels accept it ?

Oh, this is a kernel parameter, but currently:
1. The latest kernel using "clocksource=" instead of "clock=". You can check 
the Documentation/kernel-parameters.txt
2. I haven't sent out the in-kernel PIT patch... At present, KVM still using 
PIT from userspace/QEMU.

I guesses you are under heavy workload? For "sleep" in bash seems ok on 2.6.22
(x86_64, using RHEL5 as guest distro). 

>
>
> Yves.
>
>
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-- 
Thanks
Yang, Sheng

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