diff options
| -rw-r--r-- | include/linux/preempt.h | 5 | ||||
| -rw-r--r-- | include/linux/sched.h | 34 |
2 files changed, 28 insertions, 11 deletions
diff --git a/include/linux/preempt.h b/include/linux/preempt.h index 4d244e295e85..031898b38d06 100644 --- a/include/linux/preempt.h +++ b/include/linux/preempt.h @@ -122,9 +122,10 @@ * The preempt_count offset after spin_lock() */ #if !defined(CONFIG_PREEMPT_RT) -#define PREEMPT_LOCK_OFFSET PREEMPT_DISABLE_OFFSET +#define PREEMPT_LOCK_OFFSET PREEMPT_DISABLE_OFFSET #else -#define PREEMPT_LOCK_OFFSET 0 +/* Locks on RT do not disable preemption */ +#define PREEMPT_LOCK_OFFSET 0 #endif /* diff --git a/include/linux/sched.h b/include/linux/sched.h index b448c7460577..21b7cd00bf1d 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2049,19 +2049,35 @@ extern int __cond_resched_rwlock_write(rwlock_t *lock); #define MIGHT_RESCHED_RCU_SHIFT 8 #define MIGHT_RESCHED_PREEMPT_MASK ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1) -#define cond_resched_lock(lock) ({ \ - __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET); \ - __cond_resched_lock(lock); \ +#ifndef CONFIG_PREEMPT_RT +/* + * Non RT kernels have an elevated preempt count due to the held lock, + * but are not allowed to be inside a RCU read side critical section + */ +# define PREEMPT_LOCK_RESCHED_OFFSETS PREEMPT_LOCK_OFFSET +#else +/* + * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in + * cond_resched*lock() has to take that into account because it checks for + * preempt_count() and rcu_preempt_depth(). + */ +# define PREEMPT_LOCK_RESCHED_OFFSETS \ + (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT)) +#endif + +#define cond_resched_lock(lock) ({ \ + __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ + __cond_resched_lock(lock); \ }) -#define cond_resched_rwlock_read(lock) ({ \ - __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET); \ - __cond_resched_rwlock_read(lock); \ +#define cond_resched_rwlock_read(lock) ({ \ + __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ + __cond_resched_rwlock_read(lock); \ }) -#define cond_resched_rwlock_write(lock) ({ \ - __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET); \ - __cond_resched_rwlock_write(lock); \ +#define cond_resched_rwlock_write(lock) ({ \ + __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ + __cond_resched_rwlock_write(lock); \ }) static inline void cond_resched_rcu(void) |