From 6378ddb592158db4b42197f1bc8666228800e379 Mon Sep 17 00:00:00 2001 From: Venki Pallipadi Date: Wed, 30 Jan 2008 13:30:04 +0100 Subject: time: track accurate idle time with tick_sched.idle_sleeptime Current idle time in kstat is based on jiffies and is coarse grained. tick_sched.idle_sleeptime is making some attempt to keep track of idle time in a fine grained manner. But, it is not handling the time spent in interrupts fully. Make tick_sched.idle_sleeptime accurate with respect to time spent on handling interrupts and also add tick_sched.idle_lastupdate, which keeps track of last time when idle_sleeptime was updated. This statistics will be crucial for cpufreq-ondemand governor, which can shed some conservative gaurd band that is uses today while setting the frequency. The ondemand changes that uses the exact idle time is coming soon. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- include/linux/tick.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux/tick.h') diff --git a/include/linux/tick.h b/include/linux/tick.h index f4a1395e05f..0fadf95debe 100644 --- a/include/linux/tick.h +++ b/include/linux/tick.h @@ -51,8 +51,10 @@ struct tick_sched { unsigned long idle_jiffies; unsigned long idle_calls; unsigned long idle_sleeps; + int idle_active; ktime_t idle_entrytime; ktime_t idle_sleeptime; + ktime_t idle_lastupdate; ktime_t sleep_length; unsigned long last_jiffies; unsigned long next_jiffies; @@ -103,6 +105,8 @@ extern void tick_nohz_stop_sched_tick(void); extern void tick_nohz_restart_sched_tick(void); extern void tick_nohz_update_jiffies(void); extern ktime_t tick_nohz_get_sleep_length(void); +extern void tick_nohz_stop_idle(int cpu); +extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time); # else static inline void tick_nohz_stop_sched_tick(void) { } static inline void tick_nohz_restart_sched_tick(void) { } @@ -113,6 +117,8 @@ 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; } # endif /* !NO_HZ */ #endif -- cgit