Re: Xen Kernel NVidia and power save

["Jarod Wilson" <user=74@nabble.blu.org>]

 On Wed, 2008-08-20 at 15:32 -0400, Jerry Feldman wrote: 
> Thanks Jarod, 
> I have Centos 5.2 which is the RHEL 5.2 kernel. 

Yep, that'd have the rudimentary freq scaling support then. Notably 
*not* supported are Rev F (cpu family 15 in /proc/cpuinfo) AMD 
processors, due to serious issues with clock stability. You don't happen 
to be running on one of those, do you? 

I don't recall what does and doesn't work on the Intel side. Pretty sure 
anything core duo or core 2 duo, or derivative xeon processors should 
work, but earlier xeon procs... Dunno. 

--jarod 



> On 08/20/2008 03:05 PM, Jarod Wilson wrote: 
> > On Wed, 2008-08-20 at 14:55 -0400, Jerry Feldman wrote: 
> >   
> >> I found that the nvidia supplied driver would not work in a xen enabled 
> >> kernel, but it does install in the non-xen enabled version of the same 
> >> kernel. I was just wondering if anyone had the same experience. At this 
> >> point, it is not very important, more curiosity. 
> >>     
> > 
> > I believe its a known issue. 
> > 
> >   
> >> Second, I was having problems getting power save to work properly. After 
> >> playing with the nvidia driver, I booted into the non-xen enabled 
> >> kernel, and now power save is working. So, I was wondering if there is 
> >> something in the xen-enabled kernel that prevents power save from 
> >> working. I have not booted back into the xen kernel to make sure it 
> >> works or not. Ideally, the virtual machine software, whether the xen 
> >> hypervisor or VMWare or Virtualbox should handle power management, so 
> >> this is simply an RTFM question that I'll figure out next week after the 
> >> installfest when I may have some time. 
> >>     
> > 
> > One of the huge problems with the xen hypervisor is that it attempts to 
> > entirely reinvent the wheel -- which includes proper support for cpu 
> > frequecy scaling and acpi in general. 
> > 
> > In Red Hat Enterprise Linux 5.2's kernel-xen, there's rudimentary freq 
> > scaling support for certain cpus.