Re: [PATCH v2 1/5] arch_topology: Introduce thermal pressure update function
From: Bjorn Andersson <hidden>
Date: 2021-10-27 18:41:33
Also in:
linux-arm-msm, linux-pm, lkml
On Fri 15 Oct 07:45 PDT 2021, Lukasz Luba wrote:
quoted hunk ↗ jump to hunk
diff --git a/arch/arm64/include/asm/topology.h b/arch/arm64/include/asm/topology.h
[..]
+/** + * topology_thermal_pressure_update() - Update thermal pressure for CPUs + * @cpus : The related CPUs for which capacity has been reduced + * @capped_freq : The maximum allowed frequency that CPUs can run at
I know this matches what I see in e.g. the Qualcomm cpufreq hw driver, but in what cases will @capped_freq differ from cpufreq_get_hw_max_freq(cpumask_first(cpus))? Regards, Bjorn
quoted hunk ↗ jump to hunk
+ * + * Update the value of thermal pressure for all @cpus in the mask. The + * cpumask should include all (online+offline) affected CPUs, to avoid + * operating on stale data when hot-plug is used for some CPUs. The + * @capped_freq must be less or equal to the max possible frequency and + * reflects the currently allowed max CPUs frequency due to thermal capping. + * The @capped_freq must be provided in kHz. + */ +void topology_thermal_pressure_update(const struct cpumask *cpus, + unsigned long capped_freq) +{ + unsigned long max_capacity, capacity; + int cpu; + + if (!cpus) + return; + + cpu = cpumask_first(cpus); + max_capacity = arch_scale_cpu_capacity(cpu); + + /* Convert to MHz scale which is used in 'freq_factor' */ + capped_freq /= 1000; + + capacity = mult_frac(capped_freq, max_capacity, + per_cpu(freq_factor, cpu)); + + arch_set_thermal_pressure(cpus, max_capacity - capacity); +} +EXPORT_SYMBOL_GPL(topology_thermal_pressure_update); + static ssize_t cpu_capacity_show(struct device *dev, struct device_attribute *attr, char *buf)@@ -220,7 +255,6 @@ static void update_topology_flags_workfn(struct work_struct *work) update_topology = 0; } -static DEFINE_PER_CPU(u32, freq_factor) = 1; static u32 *raw_capacity; static int free_raw_capacity(void)
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