__RW_LOCK_UNLOCKED 28 include/linux/rwlock.h do { *(lock) = __RW_LOCK_UNLOCKED(lock); } while (0) __RW_LOCK_UNLOCKED 46 include/linux/rwlock_types.h #define DEFINE_RWLOCK(x) rwlock_t x = __RW_LOCK_UNLOCKED(x)