Messages in this thread Patch in this message | | | From | Waiman Long <> | Subject | [RFC PATCH v2 2/2] locking/percpu-rwsem: Mark rwsem as non-spinnable in percpu_rwsem_release() | Date | Mon, 14 May 2018 15:31:07 -0400 |
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The percpu_rwsem_release() is called when the ownership of the embedded rwsem is to be transferred to another task. The new owner, however, may take a while to get the ownership of the lock via percpu_rwsem_acquire(). During that period, the rwsem is now marked as writer-owned with no optimistic spinning.
Signed-off-by: Waiman Long <longman@redhat.com> --- include/linux/percpu-rwsem.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h index b1f37a8..dd37102 100644 --- a/include/linux/percpu-rwsem.h +++ b/include/linux/percpu-rwsem.h @@ -131,16 +131,16 @@ 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 + rwsem_set_writer_owned_nospin(&sem->rw_sem); } 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); + if (!read) + rwsem_set_writer_owned(&sem->rw_sem, current); } #endif -- 1.8.3.1
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