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| author | Peter Zijlstra <peterz@infradead.org> | 2020-12-08 10:22:16 +0100 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2020-12-09 17:08:47 +0100 |
| commit | 3379116a0ca965b00e6522c7ea3f16c9dbd8f9f9 (patch) | |
| tree | 9a369976c1259daaa296ad07e01fe8148d2df236 /kernel/locking/rwsem.c | |
| parent | Merge branch 'locking/rwsem' (diff) | |
| download | linux-3379116a0ca965b00e6522c7ea3f16c9dbd8f9f9.tar.xz linux-3379116a0ca965b00e6522c7ea3f16c9dbd8f9f9.zip | |
locking/rwsem: Better collate rwsem_read_trylock()
All users of rwsem_read_trylock() do rwsem_set_reader_owned(sem) on
success, move it into rwsem_read_trylock() proper.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201207090243.GE3040@hirez.programming.kicks-ass.net
Diffstat (limited to 'kernel/locking/rwsem.c')
| -rw-r--r-- | kernel/locking/rwsem.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index a163542d178e..5c0dc7ebace9 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -273,9 +273,16 @@ static inline void rwsem_set_nonspinnable(struct rw_semaphore *sem) static inline bool rwsem_read_trylock(struct rw_semaphore *sem) { long cnt = atomic_long_add_return_acquire(RWSEM_READER_BIAS, &sem->count); + if (WARN_ON_ONCE(cnt < 0)) rwsem_set_nonspinnable(sem); - return !(cnt & RWSEM_READ_FAILED_MASK); + + if (!(cnt & RWSEM_READ_FAILED_MASK)) { + rwsem_set_reader_owned(sem); + return true; + } + + return false; } /* @@ -1340,8 +1347,6 @@ static inline void __down_read(struct rw_semaphore *sem) if (!rwsem_read_trylock(sem)) { rwsem_down_read_slowpath(sem, TASK_UNINTERRUPTIBLE); DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem); - } else { - rwsem_set_reader_owned(sem); } } @@ -1351,8 +1356,6 @@ static inline int __down_read_interruptible(struct rw_semaphore *sem) if (IS_ERR(rwsem_down_read_slowpath(sem, TASK_INTERRUPTIBLE))) return -EINTR; DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem); - } else { - rwsem_set_reader_owned(sem); } return 0; } @@ -1363,8 +1366,6 @@ static inline int __down_read_killable(struct rw_semaphore *sem) if (IS_ERR(rwsem_down_read_slowpath(sem, TASK_KILLABLE))) return -EINTR; DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem); - } else { - rwsem_set_reader_owned(sem); } return 0; } |