linux-kernel - Re: [PATCH] cpufreq: intel_pstate: Update Balance performance EPP for Emerald Rapids

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Message-ID: <CAJZ5v0ibMvRE7OrLQO9CJh__hL7rbO-03KT7EAsAEoQxVdX4eA@mail.gmail.com>
Date: Fri, 2 Aug 2024 14:43:49 +0200
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: srinivas pandruvada <srinivas.pandruvada@...ux.intel.com>, 
	Pedro Henrique Kopper <pedro.kopper@...onical.com>
Cc: rafael@...nel.org, lenb@...nel.org, viresh.kumar@...aro.org, 
	linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] cpufreq: intel_pstate: Update Balance performance EPP for
 Emerald Rapids

On Thu, Aug 1, 2024 at 9:42 PM srinivas pandruvada
<srinivas.pandruvada@...ux.intel.com> wrote:
>
> On Thu, 2024-08-01 at 13:41 -0300, Pedro Henrique Kopper wrote:
> > On Intel Emerald Rapids machines, we ship the Energy Performance
> > Preference
> > (EPP) default for balance_performance as 128. However, during an
> > internal
> > investigation together with Intel, we have determined that 32 is a
> > more
> > suitable value. This leads to significant improvements in both
> > performance
> > and energy:
> >
> > POV-Ray: 32% faster | 12% less energy
> > OpenSSL: 12% faster | energy within 1%
> > Build Linux Kernel: 29% faster | 18% less energy
> >
> > Therefore, we should move the default EPP for balance_performance to
> > 32.
> > This is in line with what has already been done for Sapphire Rapids.
> >
> > Signed-off-by: Pedro Henrique Kopper <pedro.kopper@...onical.com>
> Acked-by: Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>

Applied as 6.11-rc material.

If I'm able to send a pull request next week, I'll push this for -rc3.
Otherwise, it'll be -rc4.

> > ---
> >  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 392a8000b238..c0278d023cfc 100644
> > --- a/drivers/cpufreq/intel_pstate.c
> > +++ b/drivers/cpufreq/intel_pstate.c
> > @@ -3405,6 +3405,7 @@ static const struct x86_cpu_id
> > intel_epp_default[] = {
> >        */
> >       X86_MATCH_VFM(INTEL_ALDERLAKE_L,
> > HWP_SET_DEF_BALANCE_PERF_EPP(102)),
> >       X86_MATCH_VFM(INTEL_SAPPHIRERAPIDS_X,
> > HWP_SET_DEF_BALANCE_PERF_EPP(32)),
> > +     X86_MATCH_VFM(INTEL_EMERALDRAPIDS_X,
> > HWP_SET_DEF_BALANCE_PERF_EPP(32)),
> >       X86_MATCH_VFM(INTEL_METEORLAKE_L,
> > HWP_SET_EPP_VALUES(HWP_EPP_POWERSAVE,
> >                     179, 64, 16)),
> >       X86_MATCH_VFM(INTEL_ARROWLAKE,
> > HWP_SET_EPP_VALUES(HWP_EPP_POWERSAVE,
>
>