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([2a01:e0a:f:6020:a8d:abc:f0ae:3066]) by smtp.gmail.com with ESMTPSA id e16-20020adffd10000000b003346db01263sm8232579wrr.104.2023.12.11.02.49.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 Dec 2023 02:49:04 -0800 (PST) From: Vincent Guittot To: linux@armlinux.org.uk, catalin.marinas@arm.com, will@kernel.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, sudeep.holla@arm.com, gregkh@linuxfoundation.org, rafael@kernel.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, viresh.kumar@linaro.org, lenb@kernel.org, robert.moore@intel.com, lukasz.luba@arm.com, ionela.voinescu@arm.com, pierre.gondois@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, linux-pm@vger.kernel.org, linux-acpi@vger.kernel.org Cc: conor.dooley@microchip.com, suagrfillet@gmail.com, ajones@ventanamicro.com, lftan@kernel.org, beata.michalska@arm.com, Vincent Guittot Subject: [PATCH v7 3/7] cpufreq/schedutil: Use a fixed reference frequency Date: Mon, 11 Dec 2023 11:48:51 +0100 Message-Id: <20231211104855.558096-4-vincent.guittot@linaro.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231211104855.558096-1-vincent.guittot@linaro.org> References: <20231211104855.558096-1-vincent.guittot@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" cpuinfo.max_freq can change at runtime because of boost as an example. This implies that the value could be different than the one that has been used when computing the capacity of a CPU. The new arch_scale_freq_ref() returns a fixed and coherent reference frequency that can be used when computing a frequency based on utilization. Use this arch_scale_freq_ref() when available and fallback to policy otherwise. Signed-off-by: Vincent Guittot Reviewed-by: Lukasz Luba Tested-by: Lukasz Luba Acked-by: Rafael J. Wysocki Reviewed-by: Dietmar Eggemann Acked-by: Viresh Kumar --- kernel/sched/cpufreq_schedutil.c | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedu= til.c index 4ee8ad70be99..95c3c097083e 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -114,6 +114,28 @@ static void sugov_deferred_update(struct sugov_policy = *sg_policy) } } =20 +/** + * get_capacity_ref_freq - get the reference frequency that has been used = to + * correlate frequency and compute capacity for a given cpufreq policy. We= use + * the CPU managing it for the arch_scale_freq_ref() call in the function. + * @policy: the cpufreq policy of the CPU in question. + * + * Return: the reference CPU frequency to compute a capacity. + */ +static __always_inline +unsigned long get_capacity_ref_freq(struct cpufreq_policy *policy) +{ + unsigned int freq =3D arch_scale_freq_ref(policy->cpu); + + if (freq) + return freq; + + if (arch_scale_freq_invariant()) + return policy->cpuinfo.max_freq; + + return policy->cur; +} + /** * get_next_freq - Compute a new frequency for a given cpufreq policy. * @sg_policy: schedutil policy object to compute the new frequency for. @@ -140,9 +162,9 @@ static unsigned int get_next_freq(struct sugov_policy *= sg_policy, unsigned long util, unsigned long max) { struct cpufreq_policy *policy =3D sg_policy->policy; - unsigned int freq =3D arch_scale_freq_invariant() ? - policy->cpuinfo.max_freq : policy->cur; + unsigned int freq; =20 + freq =3D get_capacity_ref_freq(policy); freq =3D map_util_freq(util, freq, max); =20 if (freq =3D=3D sg_policy->cached_raw_freq && !sg_policy->need_freq_updat= e) --=20 2.34.1