Function zone_put_bucket

freebsd/vm/uma_core.c:703–739

* Insert a full bucket into the specified cache. The "ws" parameter indicates * whether the bucket's contents should be counted as part of the zone's working * set. The bucket may be freed if it exceeds the bucket limit. */

 * set.  The bucket may be freed if it exceeds the bucket limit.
 */
static void
zone_put_bucket(uma_zone_t zone, int domain, uma_bucket_t bucket, void *udata,
    const bool ws)
{
	uma_zone_domain_t zdom;

	/* We don't cache empty buckets.  This can happen after a reclaim. */
	if (bucket->ub_cnt == 0)
		goto out;
	zdom = zone_domain_lock(zone, domain);

	/*
	 * Conditionally set the maximum number of items.
	 */
	zdom->uzd_nitems += bucket->ub_cnt;
	if (__predict_true(zdom->uzd_nitems < zone->uz_bucket_max)) {
		if (ws)
			zone_domain_imax_set(zdom, zdom->uzd_nitems);
		if (STAILQ_EMPTY(&zdom->uzd_buckets))
			zdom->uzd_seq = bucket->ub_seq;

		/*
		 * Try to promote reuse of recently used items.  For items
		 * protected by SMR, try to defer reuse to minimize polling.
		 */
		if (bucket->ub_seq == SMR_SEQ_INVALID)
			STAILQ_INSERT_HEAD(&zdom->uzd_buckets, bucket, ub_link);
		else
			STAILQ_INSERT_TAIL(&zdom->uzd_buckets, bucket, ub_link);
		ZDOM_UNLOCK(zdom);
		return;
	}
	zdom->uzd_nitems -= bucket->ub_cnt;
	ZDOM_UNLOCK(zdom);
out:
	bucket_free(zone, bucket, udata);
}

/* Pops an item out of a per-cpu cache bucket. */
static inline void *