linux-kernel - [PATCH v2 7/7] cpufreq: make schedutil the default for arm and arm64

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Message-Id: <20200722093732.14297-8-ionela.voinescu@arm.com>
Date:   Wed, 22 Jul 2020 10:37:32 +0100
From:   Ionela Voinescu <ionela.voinescu@....com>
To:     rjw@...ysocki.net, viresh.kumar@...aro.org,
        dietmar.eggemann@....com, catalin.marinas@....com,
        sudeep.holla@....com, will@...nel.org, linux@...linux.org.uk
Cc:     mingo@...hat.com, peterz@...radead.org, linux-pm@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        ionela.voinescu@....com,
        Valentin Schneider <valentin.schneider@....com>
Subject: [PATCH v2 7/7] cpufreq: make schedutil the default for arm and arm64

From: Valentin Schneider <valentin.schneider@....com>

schedutil is already a hard-requirement for EAS, which has lead to making
it default on arm (when CONFIG_BIG_LITTLE), see:

  commit 8fdcca8e254a ("cpufreq: Select schedutil when using big.LITTLE")

One thing worth pointing out is that schedutil isn't only relevant for
asymmetric CPU capacity systems; for instance, schedutil is the only
governor that honours util-clamp performance requests. Another good example
of this is x86 switching to using it by default in:

  commit a00ec3874e7d ("cpufreq: intel_pstate: Select schedutil as the default governor")

Arguably it should be made the default for all architectures, but it seems
better to wait for them to also gain frequency invariance powers. Make it
the default for arm && arm64 for now.

Signed-off-by: Valentin Schneider <valentin.schneider@....com>
Signed-off-by: Ionela Voinescu <ionela.voinescu@....com>
Cc: Catalin Marinas <catalin.marinas@....com>
Cc: Will Deacon <will@...nel.org>
Cc: Russell King <linux@...linux.org.uk>
Cc: Rafael J. Wysocki <rjw@...ysocki.net>
Cc: Viresh Kumar <viresh.kumar@...aro.org>
---
 drivers/cpufreq/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index e91750132552..2c7171e0b001 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -37,7 +37,7 @@ config CPU_FREQ_STAT
 choice
 	prompt "Default CPUFreq governor"
 	default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ
-	default CPU_FREQ_DEFAULT_GOV_SCHEDUTIL if BIG_LITTLE
+	default CPU_FREQ_DEFAULT_GOV_SCHEDUTIL if ARM64 || ARM
 	default CPU_FREQ_DEFAULT_GOV_SCHEDUTIL if X86_INTEL_PSTATE && SMP
 	default CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 	help
-- 
2.17.1