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 /kernel/softirq.c | |
| parent | NTP: correct inconsistent ntp interval/tick_length usage (diff) | |
| download | linux-6378ddb592158db4b42197f1bc8666228800e379.tar.xz linux-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 'kernel/softirq.c')
| -rw-r--r-- | kernel/softirq.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/kernel/softirq.c b/kernel/softirq.c index 8fe1ff40102d..d7837d45419e 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -280,9 +280,14 @@ asmlinkage void do_softirq(void) */ void irq_enter(void) { +#ifdef CONFIG_NO_HZ + int cpu = smp_processor_id(); + if (idle_cpu(cpu) && !in_interrupt()) + tick_nohz_stop_idle(cpu); +#endif __irq_enter(); #ifdef CONFIG_NO_HZ - if (idle_cpu(smp_processor_id())) + if (idle_cpu(cpu)) tick_nohz_update_jiffies(); #endif } |