diff options
Diffstat (limited to '')
| -rw-r--r-- | include/linux/rwsem.h | 9 | ||||
| -rw-r--r-- | kernel/locking/rwsem-xadd.c | 2 | ||||
| -rw-r--r-- | kernel/locking/rwsem.h | 23 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 8 |
4 files changed, 10 insertions, 32 deletions
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 2ea18a3def04..148983e21d47 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -34,12 +34,12 @@ */ struct rw_semaphore { atomic_long_t count; -#ifdef CONFIG_RWSEM_SPIN_ON_OWNER /* - * Write owner. Used as a speculative check to see - * if the owner is running on the cpu. + * Write owner or one of the read owners. Can be used as a + * speculative check to see if the owner is running on the cpu. */ struct task_struct *owner; +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER struct optimistic_spin_queue osq; /* spinner MCS lock */ #endif raw_spinlock_t wait_lock; @@ -73,13 +73,14 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem) #endif #ifdef CONFIG_RWSEM_SPIN_ON_OWNER -#define __RWSEM_OPT_INIT(lockname) , .osq = OSQ_LOCK_UNLOCKED, .owner = NULL +#define __RWSEM_OPT_INIT(lockname) , .osq = OSQ_LOCK_UNLOCKED #else #define __RWSEM_OPT_INIT(lockname) #endif #define __RWSEM_INITIALIZER(name) \ { __RWSEM_INIT_COUNT(name), \ + .owner = NULL, \ .wait_list = LIST_HEAD_INIT((name).wait_list), \ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock) \ __RWSEM_OPT_INIT(name) \ diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c index 0b1f77957240..c0500679fd2f 100644 --- a/kernel/locking/rwsem-xadd.c +++ b/kernel/locking/rwsem-xadd.c @@ -86,8 +86,8 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name, atomic_long_set(&sem->count, RWSEM_UNLOCKED_VALUE); raw_spin_lock_init(&sem->wait_lock); INIT_LIST_HEAD(&sem->wait_list); -#ifdef CONFIG_RWSEM_SPIN_ON_OWNER sem->owner = NULL; +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER osq_lock_init(&sem->osq); #endif } diff --git a/kernel/locking/rwsem.h b/kernel/locking/rwsem.h index 64877f5294e3..eb9c8534299b 100644 --- a/kernel/locking/rwsem.h +++ b/kernel/locking/rwsem.h @@ -61,7 +61,6 @@ #define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS #define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS) -#ifdef CONFIG_RWSEM_SPIN_ON_OWNER /* * All writes to owner are protected by WRITE_ONCE() to make sure that * store tearing can't happen as optimistic spinners may read and use @@ -126,7 +125,6 @@ static inline bool rwsem_has_anonymous_owner(struct task_struct *owner) * real owner or one of the real owners. The only exception is when the * unlock is done by up_read_non_owner(). */ -#define rwsem_clear_reader_owned rwsem_clear_reader_owned static inline void rwsem_clear_reader_owned(struct rw_semaphore *sem) { unsigned long val = (unsigned long)current | RWSEM_READER_OWNED @@ -135,28 +133,7 @@ static inline void rwsem_clear_reader_owned(struct rw_semaphore *sem) cmpxchg_relaxed((unsigned long *)&sem->owner, val, RWSEM_READER_OWNED | RWSEM_ANONYMOUSLY_OWNED); } -#endif - #else -static inline void rwsem_set_owner(struct rw_semaphore *sem) -{ -} - -static inline void rwsem_clear_owner(struct rw_semaphore *sem) -{ -} - -static inline void __rwsem_set_reader_owned(struct rw_semaphore *sem, - struct task_struct *owner) -{ -} - -static inline void rwsem_set_reader_owned(struct rw_semaphore *sem) -{ -} -#endif - -#ifndef rwsem_clear_reader_owned static inline void rwsem_clear_reader_owned(struct rw_semaphore *sem) { } diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index cbdfae379896..417bdd9e80fb 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1095,7 +1095,7 @@ config PROVE_LOCKING select DEBUG_SPINLOCK select DEBUG_MUTEXES select DEBUG_RT_MUTEXES if RT_MUTEXES - select DEBUG_RWSEMS if RWSEM_SPIN_ON_OWNER + select DEBUG_RWSEMS select DEBUG_WW_MUTEX_SLOWPATH select DEBUG_LOCK_ALLOC select TRACE_IRQFLAGS @@ -1199,10 +1199,10 @@ config DEBUG_WW_MUTEX_SLOWPATH config DEBUG_RWSEMS bool "RW Semaphore debugging: basic checks" - depends on DEBUG_KERNEL && RWSEM_SPIN_ON_OWNER + depends on DEBUG_KERNEL help - This debugging feature allows mismatched rw semaphore locks and unlocks - to be detected and reported. + This debugging feature allows mismatched rw semaphore locks + and unlocks to be detected and reported. config DEBUG_LOCK_ALLOC bool "Lock debugging: detect incorrect freeing of live locks" |