Re: [PATCH v2 1/5] arch_topology: Introduce thermal pressure update function

On 15-10-21, 15:45, Lukasz Luba wrote:

+/**
+ * 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

Maybe replace tabs with spaces here ?

+ *
+ * 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)

I will drop this and let the kernel crash :)

+		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;

We should make sure capped_freq > freq_factor and WARN if not. This will also
get rid of similar checks at the users.

+
+	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);

-- 
viresh

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