Function bucket_cache_reclaim

freebsd/vm/uma_core.c:1311–1361

* Reclaim cached buckets from a zone. All buckets are reclaimed if the caller * requested a drain, otherwise the per-domain caches are trimmed to either * estimated working set size. */

 * estimated working set size.
 */
static void
bucket_cache_reclaim(uma_zone_t zone, bool drain)
{
	uma_zone_domain_t zdom;
	uma_bucket_t bucket;
	long target;
	int i;

	/*
	 * Shrink the zone bucket size to ensure that the per-CPU caches
	 * don't grow too large.
	 */
	if (zone->uz_bucket_size > zone->uz_bucket_size_min)
		zone->uz_bucket_size--;

	for (i = 0; i < vm_ndomains; i++) {
		/*
		 * The cross bucket is partially filled and not part of
		 * the item count.  Reclaim it individually here.
		 */
		zdom = ZDOM_GET(zone, i);
		if ((zone->uz_flags & UMA_ZONE_SMR) == 0 || drain) {
			ZONE_CROSS_LOCK(zone);
			bucket = zdom->uzd_cross;
			zdom->uzd_cross = NULL;
			ZONE_CROSS_UNLOCK(zone);
			if (bucket != NULL)
				bucket_free(zone, bucket, NULL);
		}

		/*
		 * If we were asked to drain the zone, we are done only once
		 * this bucket cache is empty.  Otherwise, we reclaim items in
		 * excess of the zone's estimated working set size.  If the
		 * difference nitems - imin is larger than the WSS estimate,
		 * then the estimate will grow at the end of this interval and
		 * we ignore the historical average.
		 */
		ZDOM_LOCK(zdom);
		target = drain ? 0 : lmax(zdom->uzd_wss, zdom->uzd_nitems -
		    zdom->uzd_imin);
		while (zdom->uzd_nitems > target) {
			bucket = zone_fetch_bucket(zone, zdom, true);
			if (bucket == NULL)
				break;
			bucket_free(zone, bucket, NULL);
			ZDOM_LOCK(zdom);
		}
		ZDOM_UNLOCK(zdom);
	}
}

static void
keg_free_slab(uma_keg_t keg, uma_slab_t slab, int start)