| Subject: sched: Take RT softirq semantics into account in cond_resched() |
| From: Thomas Gleixner <tglx@linutronix.de> |
| Date: Thu, 14 Jul 2011 09:56:44 +0200 |
| |
| The softirq semantics work different on -RT. There is no SOFTIRQ_MASK in |
| the preemption counter which leads to the BUG_ON() statement in |
| __cond_resched_softirq(). As for -RT it is enough to perform a "normal" |
| schedule. |
| |
| Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
| --- |
| include/linux/sched.h | 4 ++++ |
| kernel/sched/core.c | 2 ++ |
| 2 files changed, 6 insertions(+) |
| |
| --- a/include/linux/sched.h |
| +++ b/include/linux/sched.h |
| @@ -2987,12 +2987,16 @@ extern int __cond_resched_lock(spinlock_ |
| __cond_resched_lock(lock); \ |
| }) |
| |
| +#ifndef CONFIG_PREEMPT_RT_FULL |
| extern int __cond_resched_softirq(void); |
| |
| #define cond_resched_softirq() ({ \ |
| ___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET); \ |
| __cond_resched_softirq(); \ |
| }) |
| +#else |
| +# define cond_resched_softirq() cond_resched() |
| +#endif |
| |
| static inline void cond_resched_rcu(void) |
| { |
| --- a/kernel/sched/core.c |
| +++ b/kernel/sched/core.c |
| @@ -4760,6 +4760,7 @@ int __cond_resched_lock(spinlock_t *lock |
| } |
| EXPORT_SYMBOL(__cond_resched_lock); |
| |
| +#ifndef CONFIG_PREEMPT_RT_FULL |
| int __sched __cond_resched_softirq(void) |
| { |
| BUG_ON(!in_softirq()); |
| @@ -4773,6 +4774,7 @@ int __sched __cond_resched_softirq(void) |
| return 0; |
| } |
| EXPORT_SYMBOL(__cond_resched_softirq); |
| +#endif |
| |
| /** |
| * yield - yield the current processor to other threads. |
