On Thu, May 4, 2023 at 10:35 AM Jan Beulich <jbeul...@suse.com> wrote: > > On 01.05.2023 21:30, Jason Andryuk wrote: > > When using HWP, some of the returned data is not applicable. In that > > case, we should just omit it to avoid confusing the user. So switch to > > printing the base and turbo frequencies since those are relevant to HWP. > > Similarly, stop printing the CPU frequencies since those do not apply. > > It vaguely feels like I have asked this before: Can you point me at a > place in the SDM where it is said that CPUID 0x16's "Maximum Frequency" > is the turbo frequency? Without such a reference I feel a little uneasy > with ...
I don't have a reference, but I found it empirically to match the "turbo" frequency. For an Intel® Core™ i7-10810U, https://ark.intel.com/content/www/us/en/ark/products/201888/intel-core-i710810u-processor-12m-cache-up-to-4-90-ghz.html Max Turbo Frequency 4.90 GHz # xenpm get-cpufreq-para cpu id : 0 affected_cpus : 0 cpuinfo frequency : base [1600000] turbo [4900000] Turbo has to be enabled to reach (close to) that frequency. >From my cover letter: This is for a 10th gen 6-core 1600 MHz base 4900 MHZ max cpu. In the default balance mode, Turbo Boost doesn't exceed 4GHz. Tweaking the energy_perf preference with `xenpm set-cpufreq-hwp balance ene:64`, I've seen the CPU hit 4.7GHz before throttling down and bouncing around between 4.3 and 4.5 GHz. Curiously the other cores read ~4GHz when turbo boost takes affect. This was done after pinning all dom0 cores, and using taskset to pin to vCPU/pCPU 11 and running a bash tightloop. > > @@ -720,10 +721,15 @@ static void print_cpufreq_para(int cpuid, struct > > xc_get_cpufreq_para *p_cpufreq) > > printf(" %d", p_cpufreq->affected_cpus[i]); > > printf("\n"); > > > > - printf("cpuinfo frequency : max [%u] min [%u] cur [%u]\n", > > - p_cpufreq->cpuinfo_max_freq, > > - p_cpufreq->cpuinfo_min_freq, > > - p_cpufreq->cpuinfo_cur_freq); > > + if ( internal ) > > + printf("cpuinfo frequency : base [%u] turbo [%u]\n", > > + p_cpufreq->cpuinfo_min_freq, > > + p_cpufreq->cpuinfo_max_freq); > > ... calling it "turbo" (and not "max") here. I'm fine with "max". I think I went with turbo since it's a value you cannot sustain but can only hit in short bursts. Regards, Jason
