[pve-devel] intel pstate: wrong cpu frequency with performance governor

[Dmitry Petuhov]

19.09.2016 01:29, Alexandre DERUMIER wrote:
> Hi,
>
> I have add some strange behaviour of some host last week, (cpu performance degrading)
>
>
> and I have found than 3 hosts of my 15 host cluster have wrong cpu frequency.
>
> All nodes are dell r630, with xeon v3 3,1ghz. (all with last bios/microcode updates , last proxmox kernel)
>
> On the 3 hosts, the frequency was stuck to 800mhz instead 3,1ghz. (note that on other host, the frequency was not stable, up and down between 3,09 && 3,2ghz....)
>
> Cpu governor is correctly set to max performance in bios + linux.
>
>
> It seem to be a problem with intel pstate driver.
>
>
> I have disabled it with intel_pstate=disable  in grub,  (also can be disable with CONFIG_X86_INTEL_PSTATE=n)
> and not frequency is super stable at 3,1ghz
>
>
> Has somebody already seen this on xeon v3 ?
Can confirm that on SandyBridge:
model name      : Intel(R) Xeon(R) CPU E5-2665 0 @ 2.40GHz
root at msv-spb-pve01:/usr/share/perl5/PVE/Storage# cat 
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq
1199906

And it's being changed based on cpu load, like actual governor is ondemand.