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([2a01:e0a:f:6020:fcf4:9d83:8d0d:39aa]) by smtp.gmail.com with ESMTPSA id q12-20020a05600c2e4c00b0040648217f4fsm2033503wmf.39.2023.10.18.09.25.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Oct 2023 09:25:49 -0700 (PDT) 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, acpica-devel@lists.linuxfoundation.org Cc: conor.dooley@microchip.com, suagrfillet@gmail.com, ajones@ventanamicro.com, lftan@kernel.org, Vincent Guittot Subject: [PATCH v3 3/6] cpufreq/schedutil: use a fixed reference frequency Date: Wed, 18 Oct 2023 18:25:37 +0200 Message-Id: <20231018162540.667646-4-vincent.guittot@linaro.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231018162540.667646-1-vincent.guittot@linaro.org> References: <20231018162540.667646-1-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 --- 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 458d359f5991..6e4030482ae8 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 +/** + * cpufreq_get_capacity_ref_freq - get the reference frequency of a given = CPU that + * has been used to correlate frequency and compute capacity. + * @policy: the cpufreq policy of the CPU in question. + * @use_current: Fallback to current freq instead of policy->cpuinfo.max_f= req. + * + * 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. @@ -140,10 +162,10 @@ 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 util =3D map_util_perf(util); + 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