BQ_LRU
bp = TAILQ_FIRST(&bufqueues[BQ_LRU]);
TAILQ_REMOVE(&bufqueues[BQ_LRU], bp,
TAILQ_INSERT_TAIL(&bufqueues[BQ_LRU], bp, b_freelist);
KDASSERT(checkfreelist(bp, &bufqueues[BQ_LRU], 1));
KDASSERT(checkfreelist(bp, &bufqueues[BQ_LRU], 0));
bufq = &bufqueues[BQ_LRU];
TAILQ_FOREACH(bp, &bufqueues[BQ_LRU].bq_queue, b_freelist) {