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-rw-r--r--include/linux/tick.h2
-rw-r--r--kernel/time/tick-sched.c11
2 files changed, 11 insertions, 2 deletions
diff --git a/include/linux/tick.h b/include/linux/tick.h
index 8cf8cfe2cc97..98921a3e1aa8 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h
@@ -126,7 +126,7 @@ static inline ktime_t tick_nohz_get_sleep_length(void)
return len;
}
static inline void tick_nohz_stop_idle(int cpu) { }
-static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return 0; }
+static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
# endif /* !NO_HZ */
#endif
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index cb02324bdb88..a4d219398167 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -20,6 +20,7 @@
#include <linux/profile.h>
#include <linux/sched.h>
#include <linux/tick.h>
+#include <linux/module.h>
#include <asm/irq_regs.h>
@@ -190,9 +191,17 @@ u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time)
{
struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
- *last_update_time = ktime_to_us(ts->idle_lastupdate);
+ if (!tick_nohz_enabled)
+ return -1;
+
+ if (ts->idle_active)
+ *last_update_time = ktime_to_us(ts->idle_lastupdate);
+ else
+ *last_update_time = ktime_to_us(ktime_get());
+
return ktime_to_us(ts->idle_sleeptime);
}
+EXPORT_SYMBOL_GPL(get_cpu_idle_time_us);
/**
* tick_nohz_stop_sched_tick - stop the idle tick from the idle task