sched: Final power vs. capacity cleanups

It is better not to think about compute capacity as being equivalent
to "CPU power".  The upcoming "power aware" scheduler work may create
confusion with the notion of energy consumption if "power" is used too
liberally.

This contains the architecture visible changes.  Incidentally, only ARM
takes advantage of the available pow^H^H^Hcapacity scaling hooks and
therefore those changes outside kernel/sched/ are confined to one ARM
specific file.  The default arch_scale_smt_power() hook is not overridden
by anyone.

Replacements are as follows:

	arch_scale_freq_power  --> arch_scale_freq_capacity
	arch_scale_smt_power   --> arch_scale_smt_capacity
	SCHED_POWER_SCALE      --> SCHED_CAPACITY_SCALE
	SCHED_POWER_SHIFT      --> SCHED_CAPACITY_SHIFT

The local usage of "power" in arch/arm/kernel/topology.c is also changed
to "capacity" as appropriate.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: linaro-kernel@lists.linaro.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Brown <broonie@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: devicetree@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/n/tip-48zba9qbznvglwelgq2cfygh@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 27 insertions, 27 deletions

diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
index 71e1fec6d31..d42a7db2223 100644
--- a/arch/arm/kernel/topology.c
+++ b/arch/arm/kernel/topology.c
@@ -26,30 +26,30 @@
 #include <asm/topology.h>
 
 /*
- * cpu power scale management
+ * cpu capacity scale management
  */
 
 /*
- * cpu power table
+ * cpu capacity table
  * This per cpu data structure describes the relative capacity of each core.
  * On a heteregenous system, cores don't have the same computation capacity
- * and we reflect that difference in the cpu_power field so the scheduler can
- * take this difference into account during load balance. A per cpu structure
- * is preferred because each CPU updates its own cpu_power field during the
- * load balance except for idle cores. One idle core is selected to run the
- * rebalance_domains for all idle cores and the cpu_power can be updated
- * during this sequence.
+ * and we reflect that difference in the cpu_capacity field so the scheduler
+ * can take this difference into account during load balance. A per cpu
+ * structure is preferred because each CPU updates its own cpu_capacity field
+ * during the load balance except for idle cores. One idle core is selected
+ * to run the rebalance_domains for all idle cores and the cpu_capacity can be
+ * updated during this sequence.
  */
 static DEFINE_PER_CPU(unsigned long, cpu_scale);
 
-unsigned long arch_scale_freq_power(struct sched_domain *sd, int cpu)
+unsigned long arch_scale_freq_capacity(struct sched_domain *sd, int cpu)
 {
 	return per_cpu(cpu_scale, cpu);
 }
 
-static void set_power_scale(unsigned int cpu, unsigned long power)
+static void set_capacity_scale(unsigned int cpu, unsigned long capacity)
 {
-	per_cpu(cpu_scale, cpu) = power;
+	per_cpu(cpu_scale, cpu) = capacity;
 }
 
 #ifdef CONFIG_OF
@@ -62,11 +62,11 @@ struct cpu_efficiency {
  * Table of relative efficiency of each processors
  * The efficiency value must fit in 20bit and the final
  * cpu_scale value must be in the range
- *   0 < cpu_scale < 3*SCHED_POWER_SCALE/2
+ *   0 < cpu_scale < 3*SCHED_CAPACITY_SCALE/2
  * in order to return at most 1 when DIV_ROUND_CLOSEST
  * is used to compute the capacity of a CPU.
  * Processors that are not defined in the table,
- * use the default SCHED_POWER_SCALE value for cpu_scale.
+ * use the default SCHED_CAPACITY_SCALE value for cpu_scale.
  */
 static const struct cpu_efficiency table_efficiency[] = {
 	{"arm,cortex-a15", 3891},
@@ -83,9 +83,9 @@ static unsigned long middle_capacity = 1;
  * Iterate all CPUs' descriptor in DT and compute the efficiency
  * (as per table_efficiency). Also calculate a middle efficiency
  * as close as possible to  (max{eff_i} - min{eff_i}) / 2
- * This is later used to scale the cpu_power field such that an
- * 'average' CPU is of middle power. Also see the comments near
- * table_efficiency[] and update_cpu_power().
+ * This is later used to scale the cpu_capacity field such that an
+ * 'average' CPU is of middle capacity. Also see the comments near
+ * table_efficiency[] and update_cpu_capacity().
  */
 static void __init parse_dt_topology(void)
 {
@@ -141,15 +141,15 @@ static void __init parse_dt_topology(void)
 	 * cpu_scale because all CPUs have the same capacity. Otherwise, we
 	 * compute a middle_capacity factor that will ensure that the capacity
 	 * of an 'average' CPU of the system will be as close as possible to
-	 * SCHED_POWER_SCALE, which is the default value, but with the
+	 * SCHED_CAPACITY_SCALE, which is the default value, but with the
 	 * constraint explained near table_efficiency[].
 	 */
 	if (4*max_capacity < (3*(max_capacity + min_capacity)))
 		middle_capacity = (min_capacity + max_capacity)
-				>> (SCHED_POWER_SHIFT+1);
+				>> (SCHED_CAPACITY_SHIFT+1);
 	else
 		middle_capacity = ((max_capacity / 3)
-				>> (SCHED_POWER_SHIFT-1)) + 1;
+				>> (SCHED_CAPACITY_SHIFT-1)) + 1;
 
 }
 
@@ -158,20 +158,20 @@ static void __init parse_dt_topology(void)
  * boot. The update of all CPUs is in O(n^2) for heteregeneous system but the
  * function returns directly for SMP system.
  */
-static void update_cpu_power(unsigned int cpu)
+static void update_cpu_capacity(unsigned int cpu)
 {
 	if (!cpu_capacity(cpu))
 		return;
 
-	set_power_scale(cpu, cpu_capacity(cpu) / middle_capacity);
+	set_capacity_scale(cpu, cpu_capacity(cpu) / middle_capacity);
 
-	printk(KERN_INFO "CPU%u: update cpu_power %lu\n",
-		cpu, arch_scale_freq_power(NULL, cpu));
+	printk(KERN_INFO "CPU%u: update cpu_capacity %lu\n",
+		cpu, arch_scale_freq_capacity(NULL, cpu));
 }
 
 #else
 static inline void parse_dt_topology(void) {}
-static inline void update_cpu_power(unsigned int cpuid) {}
+static inline void update_cpu_capacity(unsigned int cpuid) {}
 #endif
 
  /*
@@ -267,7 +267,7 @@ void store_cpu_topology(unsigned int cpuid)
 
 	update_siblings_masks(cpuid);
 
-	update_cpu_power(cpuid);
+	update_cpu_capacity(cpuid);
 
 	printk(KERN_INFO "CPU%u: thread %d, cpu %d, socket %d, mpidr %x\n",
 		cpuid, cpu_topology[cpuid].thread_id,
@@ -297,7 +297,7 @@ void __init init_cpu_topology(void)
 {
 	unsigned int cpu;
 
-	/* init core mask and power*/
+	/* init core mask and capacity */
 	for_each_possible_cpu(cpu) {
 		struct cputopo_arm *cpu_topo = &(cpu_topology[cpu]);
 
@@ -307,7 +307,7 @@ void __init init_cpu_topology(void)
 		cpumask_clear(&cpu_topo->core_sibling);
 		cpumask_clear(&cpu_topo->thread_sibling);
 
-		set_power_scale(cpu, SCHED_POWER_SCALE);
+		set_capacity_scale(cpu, SCHED_CAPACITY_SCALE);
 	}
 	smp_wmb();