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Commit b4ca4bcf authored by Dietmar Eggemann's avatar Dietmar Eggemann Committed by Dmitry Shmidt
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ANDROID: arm: Cpu invariant scheduler load-tracking and capacity support 



Provides the scheduler with a cpu scaling correction factor for more
accurate load-tracking and cpu capacity handling.

The Energy Model (EM) (in fact the capacity value of the last element
of the capacity states vector of the core (MC) level sched_group_energy
structure) is used instead of the arm arch specific cpu_efficiency and
dtb property 'clock-frequency' values as the source for this cpu
scaling factor.

The cpu capacity value depends on the micro-architecture and the
maximum frequency of the cpu.

The maximum frequency part should not be confused with the frequency
invariant scheduler load-tracking support which deals with frequency
related scaling due to DFVS functionality.

Signed-off-by: default avatarJuri Lelli <juri.lelli@arm.com>
Signed-off-by: default avatarDietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: default avatarAndres Oportus <andresoportus@google.com>
parent 858d7188

arch/arm/kernel/topology.c

+9 −3
Original line number Original line Diff line number Diff line
@@ -153,6 +153,8 @@ static void __init parse_dt_topology(void) 




}

}





static const struct sched_group_energy * const cpu_core_energy(int cpu);



/*

/*

 * Look for a customed capacity of a CPU in the cpu_capacity table during the

 * Look for a customed capacity of a CPU in the cpu_capacity table during the

 * boot. The update of all CPUs is in O(n^2) for heteregeneous system but the

 * boot. The update of all CPUs is in O(n^2) for heteregeneous system but the
@@ -160,10 +162,14 @@ static void __init parse_dt_topology(void) 
 */

 */

static void update_cpu_capacity(unsigned int cpu)

static void update_cpu_capacity(unsigned int cpu)

{

{

	if (!cpu_capacity(cpu))

	unsigned long capacity = SCHED_CAPACITY_SCALE;

		return;



	if (cpu_core_energy(cpu)) {

		int max_cap_idx = cpu_core_energy(cpu)->nr_cap_states - 1;

		capacity = cpu_core_energy(cpu)->cap_states[max_cap_idx].cap;

	}





	set_capacity_scale(cpu, cpu_capacity(cpu) / middle_capacity);

	set_capacity_scale(cpu, capacity);





	pr_info("CPU%u: update cpu_capacity %lu\n",

	pr_info("CPU%u: update cpu_capacity %lu\n",

		cpu, arch_scale_cpu_capacity(NULL, cpu));

		cpu, arch_scale_cpu_capacity(NULL, cpu));