From 75d659317bb136d849a10a30ffe7e0462c982d29 Mon Sep 17 00:00:00 2001 From: Vincent Guittot Date: Tue, 26 Mar 2024 10:16:12 +0100 Subject: cpufreq: Add a cpufreq pressure feedback for the scheduler Provide to the scheduler a feedback about the temporary max available capacity. Unlike arch_update_thermal_pressure(), this doesn't need to be filtered as the pressure will happen for dozens of ms or more. Signed-off-by: Vincent Guittot Signed-off-by: Ingo Molnar Tested-by: Lukasz Luba Reviewed-by: Qais Yousef Reviewed-by: Lukasz Luba Reviewed-by: Dhruva Gole Acked-by: Rafael J. Wysocki Acked-by: Viresh Kumar Link: https://lore.kernel.org/r/20240326091616.3696851-2-vincent.guittot@linaro.org --- drivers/cpufreq/cpufreq.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) (limited to 'drivers/cpufreq') diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 66e10a19d76a..1de8bd105934 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -2582,6 +2582,40 @@ int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) } EXPORT_SYMBOL(cpufreq_get_policy); +DEFINE_PER_CPU(unsigned long, cpufreq_pressure); + +/** + * cpufreq_update_pressure() - Update cpufreq pressure for CPUs + * @policy: cpufreq policy of the CPUs. + * + * Update the value of cpufreq pressure for all @cpus in the policy. + */ +static void cpufreq_update_pressure(struct cpufreq_policy *policy) +{ + unsigned long max_capacity, capped_freq, pressure; + u32 max_freq; + int cpu; + + cpu = cpumask_first(policy->related_cpus); + max_freq = arch_scale_freq_ref(cpu); + capped_freq = policy->max; + + /* + * Handle properly the boost frequencies, which should simply clean + * the cpufreq pressure value. + */ + if (max_freq <= capped_freq) { + pressure = 0; + } else { + max_capacity = arch_scale_cpu_capacity(cpu); + pressure = max_capacity - + mult_frac(max_capacity, capped_freq, max_freq); + } + + for_each_cpu(cpu, policy->related_cpus) + WRITE_ONCE(per_cpu(cpufreq_pressure, cpu), pressure); +} + /** * cpufreq_set_policy - Modify cpufreq policy parameters. * @policy: Policy object to modify. @@ -2637,6 +2671,8 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, policy->max = __resolve_freq(policy, policy->max, CPUFREQ_RELATION_H); trace_cpu_frequency_limits(policy); + cpufreq_update_pressure(policy); + policy->cached_target_freq = UINT_MAX; pr_debug("new min and max freqs are %u - %u kHz\n", -- cgit v1.2.3