Commit 61233580 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'pm-4.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm 

Pull power management fix from Rafael Wysocki:
 "This fixes a schedutil cpufreq governor regression from the 4.14 cycle
  that may cause a CPU idleness check to return incorrect results in
  some cases which leads to suboptimal decisions (Joel Fernandes)"

* tag 'pm-4.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: schedutil: Use idle_calls counter of the remote CPU
parents 2758b3e3 466a2b42

include/linux/tick.h

+1 −0
Original line number Diff line number Diff line
@@ -119,6 +119,7 @@ extern void tick_nohz_idle_exit(void); 
extern void tick_nohz_irq_exit(void);

extern ktime_t tick_nohz_get_sleep_length(void);

extern unsigned long tick_nohz_get_idle_calls(void);

extern unsigned long tick_nohz_get_idle_calls_cpu(int cpu);

extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);

extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);

#else /* !CONFIG_NO_HZ_COMMON */

kernel/sched/cpufreq_schedutil.c

+1 −1
Original line number Diff line number Diff line
@@ -244,7 +244,7 @@ static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, unsigned long *util, 
#ifdef CONFIG_NO_HZ_COMMON

static bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu)

{

	unsigned long idle_calls = tick_nohz_get_idle_calls();

	unsigned long idle_calls = tick_nohz_get_idle_calls_cpu(sg_cpu->cpu);

	bool ret = idle_calls == sg_cpu->saved_idle_calls;



	sg_cpu->saved_idle_calls = idle_calls;

kernel/time/tick-sched.c

+13 −0
Original line number Diff line number Diff line
@@ -985,6 +985,19 @@ ktime_t tick_nohz_get_sleep_length(void) 
	return ts->sleep_length;

}



/**

 * tick_nohz_get_idle_calls_cpu - return the current idle calls counter value

 * for a particular CPU.

 *

 * Called from the schedutil frequency scaling governor in scheduler context.

 */

unsigned long tick_nohz_get_idle_calls_cpu(int cpu)

{

	struct tick_sched *ts = tick_get_tick_sched(cpu);



	return ts->idle_calls;

}



/**

 * tick_nohz_get_idle_calls - return the current idle calls counter value

 *

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