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authorLinus Torvalds <torvalds@linux-foundation.org>2017-12-29 22:54:15 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-12-29 22:54:15 +0300
commit61233580f1f33c50e159c50e24d80ffd2ba2e06b (patch)
tree5f24b18f2a1178e3c022b59e439bd66680b56717
parent2758b3e3e630ba304fc4aca434d591e70e528298 (diff)
parent466a2b42d67644447a1765276259a3ea5531ddff (diff)
downloadlinux-61233580f1f33c50e159c50e24d80ffd2ba2e06b.tar.xz
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
-rw-r--r--include/linux/tick.h1
-rw-r--r--kernel/sched/cpufreq_schedutil.c2
-rw-r--r--kernel/time/tick-sched.c13
3 files changed, 15 insertions, 1 deletions
diff --git a/include/linux/tick.h b/include/linux/tick.h
index f442d1a42025..7cc35921218e 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h
@@ -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 */
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index 2f52ec0f1539..d6717a3331a1 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -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;
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 99578f06c8d4..77555faf6fbc 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -986,6 +986,19 @@ ktime_t tick_nohz_get_sleep_length(void)
}
/**
+ * 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
*
* Called from the schedutil frequency scaling governor in scheduler context.