From d6af602c1a87abbfc8c7a01600f97ad75f358f10 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 3 Jul 2009 08:30:20 -0500 Subject: [PATCH 126/267] timers: preempt-rt support Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- kernel/timer.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/kernel/timer.c b/kernel/timer.c index e4b2373..2aa1215 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1294,6 +1294,22 @@ unsigned long get_next_timer_interrupt(unsigned long now) */ if (cpu_is_offline(smp_processor_id())) return now + NEXT_TIMER_MAX_DELTA; + +#ifdef CONFIG_PREEMPT_RT_FULL + /* + * On PREEMPT_RT we cannot sleep here. If the trylock does not + * succeed then we return the worst-case 'expires in 1 tick' + * value: + */ + if (spin_trylock(&base->lock)) { + if (time_before_eq(base->next_timer, base->timer_jiffies)) + base->next_timer = __next_timer_interrupt(base); + expires = base->next_timer; + spin_unlock(&base->lock); + } else { + expires = now + 1; + } +#else spin_lock(&base->lock); if (time_before_eq(base->next_timer, base->timer_jiffies)) base->next_timer = __next_timer_interrupt(base); @@ -1302,7 +1318,7 @@ unsigned long get_next_timer_interrupt(unsigned long now) if (time_before_eq(expires, now)) return now; - +#endif return cmp_next_hrtimer_event(now, expires); } #endif -- 1.7.10