diff options
| author | Venki Pallipadi <venkatesh.pallipadi@intel.com> | 2008-01-30 13:30:04 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-01-30 13:30:04 +0100 |
| commit | 6378ddb592158db4b42197f1bc8666228800e379 (patch) | |
| tree | f9b1e671dfd12fb221f6140dd231ccb14cd9f27e /include/linux/tick.h | |
| parent | bbe4d18ac2e058c56adb0cd71f49d9ed3216a405 (diff) | |
| download | lwn-6378ddb592158db4b42197f1bc8666228800e379.tar.gz lwn-6378ddb592158db4b42197f1bc8666228800e379.zip | |
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 <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'include/linux/tick.h')
| -rw-r--r-- | include/linux/tick.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/tick.h b/include/linux/tick.h index f4a1395e05ff..0fadf95debe1 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 |