>>What is the suggestion - disbale the pstate driver? I think that would >>increase >>power consumption?
>>yes, this is increase power consumption. But increase stability & latencies. Note that disable pstate, don't disable dynamic frequencies. we still have classic "cpufreq" governors. with pstate, we have 2 profiles: -powersave -performance cpufreq have -powersave -ondemand -performance What I don't understand " https://www.kernel.org/doc/Documentation/cpu-freq/intel-pstate.txt "Since these policies are implemented in the driver, they are not same as the cpufreq scaling governors implementation, even if they have the same name in the cpufreq sysfs (scaling_governors). For example the "performance" policy is similar to cpufreq’s "performance" governor, but "powersave" is completely different than the cpufreq "powersave" governor. The strategy here is similar to cpufreq "ondemand", where the requested P-State is related to the system load." " for me, pstate "performance is working like cpufreq "ondemand". ----- Mail original ----- De: "aderumier" <aderum...@odiso.com> À: "dietmar" <diet...@proxmox.com> Cc: "pve-devel" <pve-devel@pve.proxmox.com> Envoyé: Mardi 20 Septembre 2016 11:05:25 Objet: Re: [pve-devel] intel pstate: wrong cpu frequency with performance governor >>What is the suggestion - disbale the pstate driver? I think that would >>increase >>power consumption? yes, this is increase power consumption. But increase stability & latencies. my old xeons (previous sandybridge) and amd, always are at maximum cpu frequency. Redhat have a special daemon "tuned", which have some tunables profiles for this (latency,bandwith, ...) >>Really? You observed retransmits because of different CPU frequency. I think >>retransmits need >>much larger speed differences, for example caused by high load (as opposed to >>idle nodes). I'm seeing a lot less retransmit since I have disable pstate. (but maybe this is because of bug where frequency was stuck low, and I have also a big cluster with a lot of vms) ----- Mail original ----- De: "dietmar" <diet...@proxmox.com> À: "aderumier" <aderum...@odiso.com>, "pve-devel" <pve-devel@pve.proxmox.com> Envoyé: Mardi 20 Septembre 2016 09:52:51 Objet: Re: [pve-devel] intel pstate: wrong cpu frequency with performance governor > I think this is the normal behavior of pstate, as they are a lower limit. > > But for virtualisation, I think it's really bad to have changing frequency. > (clock problem for example). What is the suggestion - disbale the pstate driver? I think that would increase power consumption? > Also for corosync, that mean that a loaded node will have faster frequency, > and non-loaded node low frequency. > This can give us reload corosync.conf after removing a node., because low > frequency take more time to get the corosync message than the fastest node > https://www.hastexo.com/resources/hints-and-kinks/whats-totem-retransmit-list-all-about-corosync/ > Really? You observed retransmits because of different CPU frequency. I think retransmits need much larger speed differences, for example caused by high load (as opposed to idle nodes). _______________________________________________ pve-devel mailing list pve-devel@pve.proxmox.com http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel _______________________________________________ pve-devel mailing list pve-devel@pve.proxmox.com http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
