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

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Message-ID: <Zqu6zjVMoiXwROBI@capivara>
Date: Thu, 1 Aug 2024 13:41:50 -0300
From: Pedro Henrique Kopper <pedro.kopper@...onical.com>
To: rafael@...nel.org, lenb@...nel.org, viresh.kumar@...aro.org
Cc: linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
	srinivas.pandruvada@...ux.intel.com, pedro.kopper@...onical.com
Subject: [PATCH] cpufreq: intel_pstate: Update Balance performance EPP for
 Emerald Rapids

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>
---
 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,
-- 
2.43.0