Re: Performance difference between Xen versions

[John Weekes <lists.xen@nuclearfallout.net>]

On 5/2/2011 11:43 AM, John Weekes wrote:
>
> The important thing that I missed on my end was not having the ACPI 
> processor driver selected (for some reason). I had cpufreq and ACPI 
> enabled, but I needed that, as well. 

cpufreq seems to be working now, as is xenpm (and using xenpm is much 
easier than setting the Xen command line), but I'm still not seeing 
signs that turbo mode is bumping up my CPU speed beyond the standard 
value, as I would expect it to.

Here's what it looks like when I start a single process that spins and 
gobbles down a core:

# xenpm get-cpufreq-states | grep current
current frequency    : 1600 MHz
current frequency    : 1600 MHz
current frequency    : 1600 MHz
current frequency    : 1600 MHz
current frequency    : 1600 MHz
current frequency    : 2268 MHz
current frequency    : 1600 MHz
current frequency    : 1600 MHz
current frequency    : 1600 MHz
current frequency    : 1600 MHz
current frequency    : 1600 MHz
current frequency    : 1600 MHz
current frequency    : 1600 MHz
current frequency    : 1600 MHz
current frequency    : 1600 MHz
current frequency    : 1600 MHz
current frequency    : 1600 MHz
current frequency    : 1600 MHz
current frequency    : 1600 MHz
current frequency    : 1600 MHz
current frequency    : 1600 MHz
current frequency    : 1600 MHz
current frequency    : 1600 MHz
current frequency    : 1600 MHz

And looking at the core when running at the higher speed, I see:

# xenpm get-cpufreq-para 5
cpu id               : 5
affected_cpus        : 5
cpuinfo frequency    : max [2268000] min [1600000] cur [2268000]
scaling_driver       : acpi-cpufreq
scaling_avail_gov    : userspace performance powersave ondemand
current_governor     : ondemand
   ondemand specific  :
     sampling_rate    : max [10000000] min [10000] cur [20000]
     up_threshold     : 80
scaling_avail_freq   : *2268000 2267000 2133000 2000000 1867000 1733000 
1600000
scaling frequency    : max [2268000] min [1600000] cur [2268000]
turbo mode           : enabled

Does it do it silently? If so, how can I see the true frequency?

-John