47  * to acquire the lock via optimistic spinning, but not readers. Similar
78  * groups that contain readers that acquire the lock together smaller
85  * nonspinnable bit for a given rwsem after they fail to acquire the lock
87  * acquire the write lock. Similarly, readers that observe the setting
89  * nonspinnable bits when they acquire the read lock via the wakeup path.
92  * a writer is able to acquire the rwsem in the fast path or somehow a
482 	 * to acquire the lock at the same time irrespective of their order  in rwsem_mark_wake()
483 	 * in the queue. The writers acquire the lock according to their  in rwsem_mark_wake()
603  * Try to acquire read lock before the reader is put on wait queue.
627  * Try to acquire write lock before the writer has been put on wait queue.
799 	 * Optimistically spin on the owner field and attempt to acquire the  in rwsem_optimistic_spin()
812 		 * Try to acquire the lock  in rwsem_optimistic_spin()
868 		 *    task just comes in and acquire the lock before  in rwsem_optimistic_spin()
874 		 * acquire the lock or continue spinning on the new owning  in rwsem_optimistic_spin()
911  * This give writers better chance to acquire the rwsem first before
924  * This function is called when the reader fails to acquire the lock via
936  * both cases, the reader is eligible to acquire the lock. This is the
1015 		/* rwsem_optimistic_spin() implies ACQUIRE on success */  in rwsem_down_read_slowpath()
1031 		/* rwsem_reader_phase_trylock() implies ACQUIRE on success */  in rwsem_down_read_slowpath()
1051 			/* Provide lock ACQUIRE */  in rwsem_down_read_slowpath()
1143  * Wait until we successfully acquire the write lock
1159 		/* rwsem_optimistic_spin() implies ACQUIRE on success */  in rwsem_down_write_slowpath()
1173 	 * and block until we can acquire the sem.  in rwsem_down_write_slowpath()
1225 	/* wait until we successfully acquire the lock */  in rwsem_down_write_slowpath()
1230 			/* rwsem_try_write_lock() implies ACQUIRE on success */  in rwsem_down_write_slowpath()
1237 		 * After setting the handoff bit and failing to acquire  in rwsem_down_write_slowpath()
1241 		 * In this case, we attempt to acquire the lock again  in rwsem_down_write_slowpath()