diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2007-02-16 10:27:47 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-16 17:13:58 +0100 |
| commit | fd064b9b7770d5c7705bf9542950c7bd81c30f98 (patch) | |
| tree | 8b14c81f983e49b5553fd6764139bffb1d4f1648 | |
| parent | [PATCH] Fix cascade lookup of next_timer_interrupt (diff) | |
| download | linux-fd064b9b7770d5c7705bf9542950c7bd81c30f98.tar.xz linux-fd064b9b7770d5c7705bf9542950c7bd81c30f98.zip | |
[PATCH] Extend next_timer_interrupt() to use a reference jiffie
For CONFIG_NO_HZ we need to calculate the next timer wheel event based on a
given jiffie value. Extend the existing code to allow the extra 'now'
argument. Provide a compability function for the existing implementations to
call the function with now == jiffies. (This also solves the racyness of the
original code vs. jiffies changing during the iteration.)
No functional changes to existing users of this infrastructure.
[ remove WARN_ON() that triggered on s390, by Carsten Otte <cotte@de.ibm.com> ]
[ made new helper static, Adrian Bunk <bunk@stusta.de> ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/timer.h | 10 | ||||
| -rw-r--r-- | kernel/hrtimer.c | 2 | ||||
| -rw-r--r-- | kernel/timer.c | 14 |
3 files changed, 22 insertions, 4 deletions
diff --git a/include/linux/timer.h b/include/linux/timer.h index fb5edaaf0ebd..bd0af324fd48 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -61,7 +61,17 @@ extern int del_timer(struct timer_list * timer); extern int __mod_timer(struct timer_list *timer, unsigned long expires); extern int mod_timer(struct timer_list *timer, unsigned long expires); +/* + * Return when the next timer-wheel timeout occurs (in absolute jiffies), + * locks the timer base: + */ extern unsigned long next_timer_interrupt(void); +/* + * Return when the next timer-wheel timeout occurs (in absolute jiffies), + * locks the timer base and does the comparison against the given + * jiffie. + */ +extern unsigned long get_next_timer_interrupt(unsigned long now); /** * add_timer - start a timer diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index c0fdb9b6d296..bd57ef403049 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -533,7 +533,7 @@ ktime_t hrtimer_get_remaining(const struct hrtimer *timer) } EXPORT_SYMBOL_GPL(hrtimer_get_remaining); -#ifdef CONFIG_NO_IDLE_HZ +#if defined(CONFIG_NO_IDLE_HZ) || defined(CONFIG_NO_HZ) /** * hrtimer_get_next_event - get the time until next expiry event * diff --git a/kernel/timer.c b/kernel/timer.c index 201bee07b8e0..6d843e100e75 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -591,7 +591,7 @@ static inline void __run_timers(tvec_base_t *base) spin_unlock_irq(&base->lock); } -#ifdef CONFIG_NO_IDLE_HZ +#if defined(CONFIG_NO_IDLE_HZ) || defined(CONFIG_NO_HZ) /* * Find out when the next timer event is due to happen. This * is used on S/390 to stop all activity when a cpus is idle. @@ -687,10 +687,10 @@ static unsigned long cmp_next_hrtimer_event(unsigned long now, /** * next_timer_interrupt - return the jiffy of the next pending timer */ -unsigned long next_timer_interrupt(void) +unsigned long get_next_timer_interrupt(unsigned long now) { tvec_base_t *base = __get_cpu_var(tvec_bases); - unsigned long expires, now = jiffies; + unsigned long expires; spin_lock(&base->lock); expires = __next_timer_interrupt(base); @@ -701,6 +701,14 @@ unsigned long next_timer_interrupt(void) return cmp_next_hrtimer_event(now, expires); } + +#ifdef CONFIG_NO_IDLE_HZ +unsigned long next_timer_interrupt(void) +{ + return get_next_timer_interrupt(jiffies); +} +#endif + #endif /******************************************************************/ |