[PATCH] lockdep: clean up rwsems
Clean up rwsems. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Ingo Molnar
Linus Torvalds
parent
8b3db9c542
commit
c4e05116a2
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@ -61,23 +61,11 @@ struct rw_semaphore {
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#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
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spinlock_t wait_lock;
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struct list_head wait_list;
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#if RWSEM_DEBUG
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int debug;
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#endif
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};
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/*
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* initialisation
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*/
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#if RWSEM_DEBUG
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#define __RWSEM_DEBUG_INIT , 0
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#else
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#define __RWSEM_DEBUG_INIT /* */
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#endif
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#define __RWSEM_INITIALIZER(name) \
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{ RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) \
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__RWSEM_DEBUG_INIT }
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}
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#define DECLARE_RWSEM(name) \
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struct rw_semaphore name = __RWSEM_INITIALIZER(name)
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@ -87,9 +75,6 @@ static inline void init_rwsem(struct rw_semaphore *sem)
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sem->count = RWSEM_UNLOCKED_VALUE;
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spin_lock_init(&sem->wait_lock);
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INIT_LIST_HEAD(&sem->wait_list);
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#if RWSEM_DEBUG
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sem->debug = 0;
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#endif
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}
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/*
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@ -32,22 +32,10 @@ struct rw_semaphore {
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__s32 activity;
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spinlock_t wait_lock;
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struct list_head wait_list;
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#if RWSEM_DEBUG
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int debug;
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#endif
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};
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/*
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* initialisation
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*/
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#if RWSEM_DEBUG
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#define __RWSEM_DEBUG_INIT , 0
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#else
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#define __RWSEM_DEBUG_INIT /* */
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#endif
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#define __RWSEM_INITIALIZER(name) \
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{ 0, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) __RWSEM_DEBUG_INIT }
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{ 0, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) }
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#define DECLARE_RWSEM(name) \
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struct rw_semaphore name = __RWSEM_INITIALIZER(name)
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@ -9,8 +9,6 @@
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#include <linux/linkage.h>
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#define RWSEM_DEBUG 0
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#ifdef __KERNEL__
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#include <linux/types.h>
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@ -26,23 +24,13 @@ struct rw_semaphore;
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#include <asm/rwsem.h> /* use an arch-specific implementation */
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#endif
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#ifndef rwsemtrace
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#if RWSEM_DEBUG
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extern void FASTCALL(rwsemtrace(struct rw_semaphore *sem, const char *str));
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#else
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#define rwsemtrace(SEM,FMT)
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#endif
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#endif
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/*
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* lock for reading
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*/
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static inline void down_read(struct rw_semaphore *sem)
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{
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might_sleep();
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rwsemtrace(sem,"Entering down_read");
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__down_read(sem);
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rwsemtrace(sem,"Leaving down_read");
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}
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/*
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@ -51,9 +39,7 @@ static inline void down_read(struct rw_semaphore *sem)
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static inline int down_read_trylock(struct rw_semaphore *sem)
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{
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int ret;
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rwsemtrace(sem,"Entering down_read_trylock");
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ret = __down_read_trylock(sem);
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rwsemtrace(sem,"Leaving down_read_trylock");
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return ret;
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}
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@ -63,9 +49,7 @@ static inline int down_read_trylock(struct rw_semaphore *sem)
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static inline void down_write(struct rw_semaphore *sem)
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{
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might_sleep();
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rwsemtrace(sem,"Entering down_write");
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__down_write(sem);
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rwsemtrace(sem,"Leaving down_write");
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}
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/*
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@ -74,9 +58,7 @@ static inline void down_write(struct rw_semaphore *sem)
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static inline int down_write_trylock(struct rw_semaphore *sem)
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{
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int ret;
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rwsemtrace(sem,"Entering down_write_trylock");
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ret = __down_write_trylock(sem);
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rwsemtrace(sem,"Leaving down_write_trylock");
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return ret;
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}
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@ -85,9 +67,7 @@ static inline int down_write_trylock(struct rw_semaphore *sem)
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*/
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static inline void up_read(struct rw_semaphore *sem)
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{
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rwsemtrace(sem,"Entering up_read");
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__up_read(sem);
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rwsemtrace(sem,"Leaving up_read");
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}
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/*
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@ -95,9 +75,7 @@ static inline void up_read(struct rw_semaphore *sem)
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*/
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static inline void up_write(struct rw_semaphore *sem)
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{
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rwsemtrace(sem,"Entering up_write");
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__up_write(sem);
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rwsemtrace(sem,"Leaving up_write");
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}
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/*
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@ -105,9 +83,7 @@ static inline void up_write(struct rw_semaphore *sem)
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*/
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static inline void downgrade_write(struct rw_semaphore *sem)
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{
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rwsemtrace(sem,"Entering downgrade_write");
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__downgrade_write(sem);
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rwsemtrace(sem,"Leaving downgrade_write");
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}
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#endif /* __KERNEL__ */
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@ -0,0 +1,105 @@
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/* kernel/rwsem.c: R/W semaphores, public implementation
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*
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* Written by David Howells (dhowells@redhat.com).
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* Derived from asm-i386/semaphore.h
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*/
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/rwsem.h>
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#include <asm/system.h>
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#include <asm/atomic.h>
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/*
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* lock for reading
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*/
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void down_read(struct rw_semaphore *sem)
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{
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might_sleep();
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rwsem_acquire_read(&sem->dep_map, 0, 0, _RET_IP_);
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__down_read(sem);
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}
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EXPORT_SYMBOL(down_read);
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/*
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* trylock for reading -- returns 1 if successful, 0 if contention
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*/
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int down_read_trylock(struct rw_semaphore *sem)
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{
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int ret = __down_read_trylock(sem);
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if (ret == 1)
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rwsem_acquire_read(&sem->dep_map, 0, 1, _RET_IP_);
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return ret;
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}
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EXPORT_SYMBOL(down_read_trylock);
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/*
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* lock for writing
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*/
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void down_write(struct rw_semaphore *sem)
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{
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might_sleep();
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rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_);
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__down_write(sem);
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}
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EXPORT_SYMBOL(down_write);
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/*
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* trylock for writing -- returns 1 if successful, 0 if contention
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*/
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int down_write_trylock(struct rw_semaphore *sem)
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{
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int ret = __down_write_trylock(sem);
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if (ret == 1)
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rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_);
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return ret;
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}
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EXPORT_SYMBOL(down_write_trylock);
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/*
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* release a read lock
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*/
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void up_read(struct rw_semaphore *sem)
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{
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rwsem_release(&sem->dep_map, 1, _RET_IP_);
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__up_read(sem);
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}
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EXPORT_SYMBOL(up_read);
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/*
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* release a write lock
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*/
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void up_write(struct rw_semaphore *sem)
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{
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rwsem_release(&sem->dep_map, 1, _RET_IP_);
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__up_write(sem);
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}
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EXPORT_SYMBOL(up_write);
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/*
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* downgrade write lock to read lock
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*/
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void downgrade_write(struct rw_semaphore *sem)
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{
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/*
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* lockdep: a downgraded write will live on as a write
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* dependency.
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*/
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__downgrade_write(sem);
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}
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EXPORT_SYMBOL(downgrade_write);
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@ -17,16 +17,6 @@ struct rwsem_waiter {
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#define RWSEM_WAITING_FOR_WRITE 0x00000002
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};
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#if RWSEM_DEBUG
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void rwsemtrace(struct rw_semaphore *sem, const char *str)
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{
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if (sem->debug)
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printk("[%d] %s({%d,%d})\n",
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current->pid, str, sem->activity,
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list_empty(&sem->wait_list) ? 0 : 1);
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}
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#endif
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/*
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* initialise the semaphore
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*/
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@ -35,9 +25,6 @@ void fastcall init_rwsem(struct rw_semaphore *sem)
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sem->activity = 0;
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spin_lock_init(&sem->wait_lock);
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INIT_LIST_HEAD(&sem->wait_list);
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#if RWSEM_DEBUG
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sem->debug = 0;
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#endif
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}
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/*
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@ -56,8 +43,6 @@ __rwsem_do_wake(struct rw_semaphore *sem, int wakewrite)
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struct task_struct *tsk;
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int woken;
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rwsemtrace(sem, "Entering __rwsem_do_wake");
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waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list);
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if (!wakewrite) {
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@ -104,7 +89,6 @@ __rwsem_do_wake(struct rw_semaphore *sem, int wakewrite)
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sem->activity += woken;
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out:
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rwsemtrace(sem, "Leaving __rwsem_do_wake");
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return sem;
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}
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@ -138,8 +122,6 @@ void fastcall __sched __down_read(struct rw_semaphore *sem)
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struct rwsem_waiter waiter;
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struct task_struct *tsk;
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rwsemtrace(sem, "Entering __down_read");
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spin_lock_irq(&sem->wait_lock);
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if (sem->activity >= 0 && list_empty(&sem->wait_list)) {
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@ -171,9 +153,8 @@ void fastcall __sched __down_read(struct rw_semaphore *sem)
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}
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tsk->state = TASK_RUNNING;
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out:
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rwsemtrace(sem, "Leaving __down_read");
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;
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}
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/*
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@ -184,7 +165,6 @@ int fastcall __down_read_trylock(struct rw_semaphore *sem)
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unsigned long flags;
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int ret = 0;
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rwsemtrace(sem, "Entering __down_read_trylock");
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spin_lock_irqsave(&sem->wait_lock, flags);
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@ -196,7 +176,6 @@ int fastcall __down_read_trylock(struct rw_semaphore *sem)
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spin_unlock_irqrestore(&sem->wait_lock, flags);
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rwsemtrace(sem, "Leaving __down_read_trylock");
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return ret;
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}
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@ -209,8 +188,6 @@ void fastcall __sched __down_write(struct rw_semaphore *sem)
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struct rwsem_waiter waiter;
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struct task_struct *tsk;
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rwsemtrace(sem, "Entering __down_write");
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spin_lock_irq(&sem->wait_lock);
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if (sem->activity == 0 && list_empty(&sem->wait_list)) {
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@ -242,9 +219,8 @@ void fastcall __sched __down_write(struct rw_semaphore *sem)
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}
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tsk->state = TASK_RUNNING;
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out:
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rwsemtrace(sem, "Leaving __down_write");
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;
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}
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/*
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@ -255,8 +231,6 @@ int fastcall __down_write_trylock(struct rw_semaphore *sem)
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unsigned long flags;
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int ret = 0;
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rwsemtrace(sem, "Entering __down_write_trylock");
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spin_lock_irqsave(&sem->wait_lock, flags);
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if (sem->activity == 0 && list_empty(&sem->wait_list)) {
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@ -267,7 +241,6 @@ int fastcall __down_write_trylock(struct rw_semaphore *sem)
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spin_unlock_irqrestore(&sem->wait_lock, flags);
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rwsemtrace(sem, "Leaving __down_write_trylock");
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return ret;
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}
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@ -278,16 +251,12 @@ void fastcall __up_read(struct rw_semaphore *sem)
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{
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unsigned long flags;
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rwsemtrace(sem, "Entering __up_read");
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spin_lock_irqsave(&sem->wait_lock, flags);
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if (--sem->activity == 0 && !list_empty(&sem->wait_list))
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sem = __rwsem_wake_one_writer(sem);
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spin_unlock_irqrestore(&sem->wait_lock, flags);
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rwsemtrace(sem, "Leaving __up_read");
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}
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/*
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@ -297,8 +266,6 @@ void fastcall __up_write(struct rw_semaphore *sem)
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{
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unsigned long flags;
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rwsemtrace(sem, "Entering __up_write");
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spin_lock_irqsave(&sem->wait_lock, flags);
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sem->activity = 0;
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@ -306,8 +273,6 @@ void fastcall __up_write(struct rw_semaphore *sem)
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sem = __rwsem_do_wake(sem, 1);
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spin_unlock_irqrestore(&sem->wait_lock, flags);
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rwsemtrace(sem, "Leaving __up_write");
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}
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/*
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@ -318,8 +283,6 @@ void fastcall __downgrade_write(struct rw_semaphore *sem)
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{
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unsigned long flags;
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rwsemtrace(sem, "Entering __downgrade_write");
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spin_lock_irqsave(&sem->wait_lock, flags);
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sem->activity = 1;
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@ -327,8 +290,6 @@ void fastcall __downgrade_write(struct rw_semaphore *sem)
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sem = __rwsem_do_wake(sem, 0);
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spin_unlock_irqrestore(&sem->wait_lock, flags);
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rwsemtrace(sem, "Leaving __downgrade_write");
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}
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EXPORT_SYMBOL(init_rwsem);
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@ -339,6 +300,3 @@ EXPORT_SYMBOL(__down_write_trylock);
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EXPORT_SYMBOL(__up_read);
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EXPORT_SYMBOL(__up_write);
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EXPORT_SYMBOL(__downgrade_write);
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#if RWSEM_DEBUG
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EXPORT_SYMBOL(rwsemtrace);
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#endif
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31
lib/rwsem.c
31
lib/rwsem.c
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@ -16,17 +16,6 @@ struct rwsem_waiter {
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#define RWSEM_WAITING_FOR_WRITE 0x00000002
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};
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#if RWSEM_DEBUG
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#undef rwsemtrace
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void rwsemtrace(struct rw_semaphore *sem, const char *str)
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{
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printk("sem=%p\n", sem);
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printk("(sem)=%08lx\n", sem->count);
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if (sem->debug)
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printk("[%d] %s({%08lx})\n", current->pid, str, sem->count);
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}
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#endif
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/*
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* handle the lock release when processes blocked on it that can now run
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* - if we come here from up_xxxx(), then:
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@ -45,8 +34,6 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading)
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struct list_head *next;
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signed long oldcount, woken, loop;
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rwsemtrace(sem, "Entering __rwsem_do_wake");
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if (downgrading)
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goto dont_wake_writers;
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@ -127,7 +114,6 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading)
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next->prev = &sem->wait_list;
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out:
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rwsemtrace(sem, "Leaving __rwsem_do_wake");
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return sem;
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/* undo the change to count, but check for a transition 1->0 */
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@ -186,13 +172,9 @@ rwsem_down_read_failed(struct rw_semaphore *sem)
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{
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struct rwsem_waiter waiter;
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rwsemtrace(sem, "Entering rwsem_down_read_failed");
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waiter.flags = RWSEM_WAITING_FOR_READ;
|
||||
rwsem_down_failed_common(sem, &waiter,
|
||||
RWSEM_WAITING_BIAS - RWSEM_ACTIVE_BIAS);
|
||||
|
||||
rwsemtrace(sem, "Leaving rwsem_down_read_failed");
|
||||
return sem;
|
||||
}
|
||||
|
||||
|
|
@ -204,12 +186,9 @@ rwsem_down_write_failed(struct rw_semaphore *sem)
|
|||
{
|
||||
struct rwsem_waiter waiter;
|
||||
|
||||
rwsemtrace(sem, "Entering rwsem_down_write_failed");
|
||||
|
||||
waiter.flags = RWSEM_WAITING_FOR_WRITE;
|
||||
rwsem_down_failed_common(sem, &waiter, -RWSEM_ACTIVE_BIAS);
|
||||
|
||||
rwsemtrace(sem, "Leaving rwsem_down_write_failed");
|
||||
return sem;
|
||||
}
|
||||
|
||||
|
|
@ -221,8 +200,6 @@ struct rw_semaphore fastcall *rwsem_wake(struct rw_semaphore *sem)
|
|||
{
|
||||
unsigned long flags;
|
||||
|
||||
rwsemtrace(sem, "Entering rwsem_wake");
|
||||
|
||||
spin_lock_irqsave(&sem->wait_lock, flags);
|
||||
|
||||
/* do nothing if list empty */
|
||||
|
|
@ -231,8 +208,6 @@ struct rw_semaphore fastcall *rwsem_wake(struct rw_semaphore *sem)
|
|||
|
||||
spin_unlock_irqrestore(&sem->wait_lock, flags);
|
||||
|
||||
rwsemtrace(sem, "Leaving rwsem_wake");
|
||||
|
||||
return sem;
|
||||
}
|
||||
|
||||
|
|
@ -245,8 +220,6 @@ struct rw_semaphore fastcall *rwsem_downgrade_wake(struct rw_semaphore *sem)
|
|||
{
|
||||
unsigned long flags;
|
||||
|
||||
rwsemtrace(sem, "Entering rwsem_downgrade_wake");
|
||||
|
||||
spin_lock_irqsave(&sem->wait_lock, flags);
|
||||
|
||||
/* do nothing if list empty */
|
||||
|
|
@ -255,7 +228,6 @@ struct rw_semaphore fastcall *rwsem_downgrade_wake(struct rw_semaphore *sem)
|
|||
|
||||
spin_unlock_irqrestore(&sem->wait_lock, flags);
|
||||
|
||||
rwsemtrace(sem, "Leaving rwsem_downgrade_wake");
|
||||
return sem;
|
||||
}
|
||||
|
||||
|
|
@ -263,6 +235,3 @@ EXPORT_SYMBOL(rwsem_down_read_failed);
|
|||
EXPORT_SYMBOL(rwsem_down_write_failed);
|
||||
EXPORT_SYMBOL(rwsem_wake);
|
||||
EXPORT_SYMBOL(rwsem_downgrade_wake);
|
||||
#if RWSEM_DEBUG
|
||||
EXPORT_SYMBOL(rwsemtrace);
|
||||
#endif
|
||||
|
|
|
|||
Reference in New Issue