LRU_ROTATE, /* item referenced, give another pass */
LRU_SKIP, /* item cannot be locked, skip */
LRU_RETRY, /* item not freeable. May drop the lock
LRU_ROTATE, /* item referenced, give another pass */
LRU_SKIP, /* item cannot be locked, skip */
LRU_RETRY, /* item not freeable. May drop the lock