From 55cc156505f2e43fa45dbd4bfe8f9c9d848ca44c Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Tue, 21 Jul 2015 20:26:44 +0200 Subject: [PATCH] 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: Oleg Nesterov --- include/linux/percpu-rwsem.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h index 16c30cd33501..834c4e52cb2d 100644 --- a/include/linux/percpu-rwsem.h +++ b/include/linux/percpu-rwsem.h @@ -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); +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER + if (!read) + sem->rw_sem.owner = NULL; +#endif +} + +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); +} + #endif -- 2.20.1