Commit 25980c7a authored by Valentin Schneider's avatar Valentin Schneider Committed by Peter Zijlstra
Browse files

arch_topology, sched/core: Cleanup thermal pressure definition 



The following commit:

  14533a16 ("thermal/cpu-cooling, sched/core: Move the arch_set_thermal_pressure() API to generic scheduler code")

moved the definition of arch_set_thermal_pressure() to sched/core.c, but
kept its declaration in linux/arch_topology.h. When building e.g. an x86
kernel with CONFIG_SCHED_THERMAL_PRESSURE=y, cpufreq_cooling.c ends up
getting the declaration of arch_set_thermal_pressure() from
include/linux/arch_topology.h, which is somewhat awkward.

On top of this, sched/core.c unconditionally defines
o The thermal_pressure percpu variable
o arch_set_thermal_pressure()

while arch_scale_thermal_pressure() does nothing unless redefined by the
architecture.

arch_*() functions are meant to be defined by architectures, so revert the
aforementioned commit and re-implement it in a way that keeps
arch_set_thermal_pressure() architecture-definable, and doesn't define the
thermal pressure percpu variable for kernels that don't need
it (CONFIG_SCHED_THERMAL_PRESSURE=n).

Signed-off-by: default avatarValentin Schneider <valentin.schneider@arm.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200712165917.9168-2-valentin.schneider@arm.com
parent 2705937a

arch/arm/include/asm/topology.h

+2 −1
Original line number Diff line number Diff line
@@ -16,8 +16,9 @@ 
/* Enable topology flag updates */

#define arch_update_cpu_topology topology_update_cpu_topology



/* Replace task scheduler's default thermal pressure retrieve API */

/* Replace task scheduler's default thermal pressure API */

#define arch_scale_thermal_pressure topology_get_thermal_pressure

#define arch_set_thermal_pressure   topology_set_thermal_pressure



#else

arch/arm64/include/asm/topology.h

+2 −1
Original line number Diff line number Diff line
@@ -34,8 +34,9 @@ void topology_scale_freq_tick(void); 
/* Enable topology flag updates */

#define arch_update_cpu_topology topology_update_cpu_topology



/* Replace task scheduler's default thermal pressure retrieve API */

/* Replace task scheduler's default thermal pressure API */

#define arch_scale_thermal_pressure topology_get_thermal_pressure

#define arch_set_thermal_pressure   topology_set_thermal_pressure



#include <asm-generic/topology.h>

drivers/base/arch_topology.c

+11 −0
Original line number Diff line number Diff line
@@ -54,6 +54,17 @@ void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity) 
	per_cpu(cpu_scale, cpu) = capacity;

}



DEFINE_PER_CPU(unsigned long, thermal_pressure);



void topology_set_thermal_pressure(const struct cpumask *cpus,

			       unsigned long th_pressure)

{

	int cpu;



	for_each_cpu(cpu, cpus)

		WRITE_ONCE(per_cpu(thermal_pressure, cpu), th_pressure);

}



static ssize_t cpu_capacity_show(struct device *dev,

				 struct device_attribute *attr,

				 char *buf)

include/linux/arch_topology.h

+2 −2
Original line number Diff line number Diff line
@@ -39,7 +39,7 @@ static inline unsigned long topology_get_thermal_pressure(int cpu) 
	return per_cpu(thermal_pressure, cpu);

}



void arch_set_thermal_pressure(struct cpumask *cpus,

void topology_set_thermal_pressure(const struct cpumask *cpus,

				   unsigned long th_pressure);



struct cpu_topology {

include/linux/sched/topology.h

+7 −0
Original line number Diff line number Diff line
@@ -232,6 +232,13 @@ unsigned long arch_scale_thermal_pressure(int cpu) 
}

#endif



#ifndef arch_set_thermal_pressure

static __always_inline

void arch_set_thermal_pressure(const struct cpumask *cpus,

			       unsigned long th_pressure)

{ }

#endif



static inline int task_node(const struct task_struct *p)

{

	return cpu_to_node(task_cpu(p));

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