arch_topology, sched/core: Cleanup thermal pressure definition

The following commit: 14533a16c46d ("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).

Valentin Schneider committed 6 years ago

Commit 25980c71 parent 27059376 files · +24 −15Browse files

Unified · Split

6 files

arch/arm/include/asm/topology.h +2 −1
arch/arm64/include/asm/topology.h +2 −1
drivers/base/arch_topology.c +11 −0
include/linux/arch_topology.h +2 −2
include/linux/sched/topology.h +7 −0
kernel/sched/core.c +0 −11

arch/arm/include/asm/topology.h+2−1

@@ -16,8 +16,9 @@ · 15 unmodified lines
16	16	/* Enable topology flag updates */
17	17	#define arch_update_cpu_topology topology_update_cpu_topology
18	18
19		−/* Replace task scheduler's default thermal pressure retrieve API */
	19	+/* Replace task scheduler's default thermal pressure API */
20	20	#define arch_scale_thermal_pressure topology_get_thermal_pressure
	21	+#define arch_set_thermal_pressure topology_set_thermal_pressure
21	22
22	23	#else
23	24

arch/arm64/include/asm/topology.h+2−1

@@ -34,8 +34,9 @@ void topology_scale_freq_tick(void); · 33 unmodified lines
34	34	/* Enable topology flag updates */
35	35	#define arch_update_cpu_topology topology_update_cpu_topology
36	36
37		−/* Replace task scheduler's default thermal pressure retrieve API */
	37	+/* Replace task scheduler's default thermal pressure API */
38	38	#define arch_scale_thermal_pressure topology_get_thermal_pressure
	39	+#define arch_set_thermal_pressure topology_set_thermal_pressure
39	40
40	41	#include <asm-generic/topology.h>
41	42

drivers/base/arch_topology.c+11−0

@@ -54,6 +54,17 @@ void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity) · 53 unmodified lines
54	54	per_cpu(cpu_scale, cpu) = capacity;
55	55	}
56	56
	57	+DEFINE_PER_CPU(unsigned long, thermal_pressure);
	58	+
	59	+void topology_set_thermal_pressure(const struct cpumask *cpus,
	60	+ unsigned long th_pressure)
	61	+{
	62	+ int cpu;
	63	+
	64	+ for_each_cpu(cpu, cpus)
	65	+ WRITE_ONCE(per_cpu(thermal_pressure, cpu), th_pressure);
	66	+}
	67	+
57	68	static ssize_t cpu_capacity_show(struct device *dev,
58	69	struct device_attribute *attr,
59	70	char *buf)

include/linux/arch_topology.h+2−2

@@ -39,8 +39,8 @@ static inline unsigned long topology_get_thermal_pressure(int cpu) · 38 unmodified lines
39	39	return per_cpu(thermal_pressure, cpu);
40	40	}
41	41
42		−void arch_set_thermal_pressure(struct cpumask *cpus,
43		− unsigned long th_pressure);
	42	+void topology_set_thermal_pressure(const struct cpumask *cpus,
	43	+ unsigned long th_pressure);
44	44
45	45	struct cpu_topology {
46	46	int thread_id;

include/linux/sched/topology.h+7−0

@@ -232,6 +232,13 @@ unsigned long arch_scale_thermal_pressure(int cpu) · 231 unmodified lines
232	232	}
233	233	#endif
234	234
	235	+#ifndef arch_set_thermal_pressure
	236	+static __always_inline
	237	+void arch_set_thermal_pressure(const struct cpumask *cpus,
	238	+ unsigned long th_pressure)
	239	+{ }
	240	+#endif
	241	+
235	242	static inline int task_node(const struct task_struct *p)
236	243	{
237	244	return cpu_to_node(task_cpu(p));

kernel/sched/core.c+0−11

@@ -3869,17 +3869,6 @@ unsigned long long task_sched_runtime(struct task_struct *p) · 3868 unmodified lines
3869	3869	return ns;
3870	3870	}
3871	3871
3872		−DEFINE_PER_CPU(unsigned long, thermal_pressure);
3873		−
3874		−void arch_set_thermal_pressure(struct cpumask *cpus,
3875		− unsigned long th_pressure)
3876		−{
3877		− int cpu;
3878		−
3879		− for_each_cpu(cpu, cpus)
3880		− WRITE_ONCE(per_cpu(thermal_pressure, cpu), th_pressure);
3881		−}
3882		−
3883	3872	/*
3884	3873	* This function gets called by the timer code, with HZ frequency.
3885	3874	* We call it with interrupts disabled.