[CentOS] Questions on cpu frequency scaling AMD vs. Intel

Sun Aug 3 14:31:19 UTC 2008
Kai Schaetzl <maillists at conactive.com>

Kai Schaetzl wrote on Sun, 03 Aug 2008 14:31:19 +0200:

> I have a somewhat related question. That very new AMD CPU mentioned above 
> was not recognized by CentOS 5.2 and the current frequency was shown as 
> 800000 (instead of 2500000), although it was running in full speed. The 
> latest kernel corrected this.

Actually, not the latest kernel. The CentOS xen boot (hypervisor) kernel 
/xen.gz-2.6.18-92.1.6.el5 (and maybe earlier) ones calculates the frequency 
correct, the Xen 3.2 boot kernel (xen.gz-3.2) from the Xen 3.2 package 
offered at xen.org does not. Might there be a kernel parameter or other 
measure that could correct this? (I don't want to recompile any kernels.)
I wondered if it also the source of the inability to scale up on demand with 
the Intel CPUs and the 2000000 reported is actually wrong. But there is no 
change between the two boot kernels.


Kai Schätzl, Berlin, Germany
Get your web at Conactive Internet Services: http://www.conactive.com