Messages in this thread | | | From | "Rafael J. Wysocki" <> | Date | Thu, 23 Feb 2023 19:54:11 +0100 | Subject | Re: [PATCH] cpufreq: intel_pstate: Update Balance performance EPP for Sapphire Rapids |
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On Wed, Feb 22, 2023 at 7:45 AM Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> wrote: > > While majority of server OS distributions are deployed with performance > governor as the default, some distributions like Ubuntu uses powersave > governor as the default. > > While the powersave governor has much lower power, the performance is > lower than +25% for several workloads compared to performance governor. > > One report is published by www.Phoronix.com showing difference of 37%. > > The goal here is to keep mean performance delta of powersave governor > from performance governor around 10% to 12% by running wide variety > of server workloads. For some bursty workload, this delta can be still > large, as ramp up of frequency will still lag with powersave governor > irrespective of EPP setting. The performance governor always requests > maximum frequency. > > Based on experiments, EPP of 0x00, 0x10, 0x20, the performance delta for > powersave governor is around 12%. But the EPP 0x20 has 18% lower average > power. > > Also experimets are done by raising intel_pstate sysfs min_perf_pct as > high as 50%. This didn't bring in any additional improvements compared > to just changing EPP. > > From the Alder Lake processor generation, intel_pstate driver has > capability to update EPP for the default balance_performance based > on the CPU model. Use the same method to update the default > balance_performance EPP for the Sapphire Rapids processor to 0x20. > > Link: https://www.phoronix.com/review/centos-clear-spr/6 > Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> > --- > drivers/cpufreq/intel_pstate.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c > index fd73d6d2b808..32a4004d155d 100644 > --- a/drivers/cpufreq/intel_pstate.c > +++ b/drivers/cpufreq/intel_pstate.c > @@ -3372,6 +3372,7 @@ static const struct x86_cpu_id intel_epp_balance_perf[] = { > * AlderLake Mobile CPUs. > */ > X86_MATCH_INTEL_FAM6_MODEL(ALDERLAKE_L, 102), > + X86_MATCH_INTEL_FAM6_MODEL(SAPPHIRERAPIDS_X, 32), > {} > }; > > --
Applied as 6.3-rc material with some edits in the subject and changelog.
Thanks!
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