rwsem_acquire_read  459 include/linux/lockdep.h #  define rwsem_acquire_read(l, s, t, i)	lock_acquire(l, s, t, 1, 2, NULL, i)
rwsem_acquire_read  462 include/linux/lockdep.h #  define rwsem_acquire_read(l, s, t, i)	lock_acquire(l, s, t, 1, 1, NULL, i)
rwsem_acquire_read  467 include/linux/lockdep.h # define rwsem_acquire_read(l, s, t, i)		do { } while (0)