Commit 55cc1565 authored by Oleg Nesterov's avatar Oleg Nesterov

percpu-rwsem: introduce percpu_rwsem_release() and percpu_rwsem_acquire()

Add percpu_rwsem_release() and percpu_rwsem_acquire() for the users
which need to return to userspace with percpu-rwsem lock held and/or
pass the ownership to another thread.

TODO: change percpu_rwsem_release() to use rwsem_clear_owner(). We can
either fold kernel/locking/rwsem.h into include/linux/rwsem.h, or add
the non-inline percpu_rwsem_clear_owner().
Signed-off-by: default avatarOleg Nesterov <>
parent 9287f692
......@@ -32,4 +32,23 @@ extern void percpu_free_rwsem(struct percpu_rw_semaphore *);
__percpu_init_rwsem(brw, #brw, &rwsem_key); \
#define percpu_rwsem_is_held(sem) lockdep_is_held(&(sem)->rw_sem)
static inline void percpu_rwsem_release(struct percpu_rw_semaphore *sem,
bool read, unsigned long ip)
lock_release(&sem->rw_sem.dep_map, 1, ip);
if (!read)
sem->rw_sem.owner = NULL;
static inline void percpu_rwsem_acquire(struct percpu_rw_semaphore *sem,
bool read, unsigned long ip)
lock_acquire(&sem->rw_sem.dep_map, 0, 1, read, 1, NULL, ip);
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