Subject: sched: Take RT softirq semantics into account in cond_resched() From: Thomas Gleixner Date: Thu, 14 Jul 2011 09:56:44 +0200 Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.8/older/patches-4.8.14-rt9.tar.xz 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 --- 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 @@ -3258,12 +3258,16 @@ 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 @@ -5021,6 +5021,7 @@ 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()); @@ -5034,6 +5035,7 @@ int __sched __cond_resched_softirq(void) return 0; } EXPORT_SYMBOL(__cond_resched_softirq); +#endif /** * yield - yield the current processor to other threads.