Re: [discuss] Re: [PATCH] Allow all Opteron processors to change pstate at same time

[Andi Kleen]

On Wednesday 12 July 2006 16:06, Joachim Deguara wrote:
> On Tue, 2006-07-11 at 14:55 +0200, Joachim Deguara wrote:
> > Here are some initial findings. 
> 
> Here are the further findings after letting the machine toggle between
> 1GHz and 2.2Ghz every two seconds for roughly 24 hours.  Unfortunately
> there is an oops after bringing CPU2 online and CPU3 will not come
> online.  

Perhaps Mark/Jacob can take a look at the oops.

> Still the differences in TSC are not bad: 

Think: any difference you get for 24h will be 10x when the system runs 10 times longer
and 365 times when the system runs for a year (and there are Linux systems
who run much longer than a year) 

Also even small non monotonies between CPUs in gettimeofday can cause big trouble.

-Andi

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