X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=rculfhash.c;h=a736b868ae7dac21c1d4d60d561cfcfbb1d223e9;hb=194fdbd18a42d2c23f4a53cc692f1fa03d31ec64;hp=c7b9ea895cf6594d11a9ef8a56a461ba3bc2ae7d;hpb=f4a9cc0b4bc9791e18c66b00023ae4ef76befb74;p=urcu.git

diff --git a/rculfhash.c b/rculfhash.c
index c7b9ea8..a736b86 100644
--- a/rculfhash.c
+++ b/rculfhash.c
@@ -724,7 +724,12 @@ struct _cds_lfht_node *lookup_bucket(struct cds_lfht *ht, unsigned long size,
 
 	assert(size > 0);
 	index = hash & (size - 1);
-	order = get_count_order_ulong(index + 1);
+	/*
+	 * equivalent to get_count_order_ulong(index + 1), but optimizes
+	 * away the non-existing 0 special-case for
+	 * get_count_order_ulong.
+	 */
+	order = fls_ulong(index);
 
 	dbg_printf("lookup hash %lu index %lu order %lu aridx %lu\n",
 		   hash, index, order, index & (!order ? 0 : ((1UL << (order - 1)) - 1)));
@@ -855,7 +860,7 @@ struct cds_lfht_node *_cds_lfht_add(struct cds_lfht *ht,
 				enum add_mode mode, int dummy)
 {
 	struct cds_lfht_node *iter_prev, *iter, *next, *new_node, *new_next,
-			*dummy_node, *return_node;
+			*return_node;
 	struct _cds_lfht_node *lookup;
 
 	assert(!is_dummy(node));
@@ -882,11 +887,15 @@ struct cds_lfht_node *_cds_lfht_add(struct cds_lfht *ht,
 				goto insert;
 			if (likely(clear_flag(iter)->p.reverse_hash > node->p.reverse_hash))
 				goto insert;
+			/* dummy node is the first node of the identical-hash-value chain */
+			if (dummy && clear_flag(iter)->p.reverse_hash == node->p.reverse_hash)
+				goto insert;
 			next = rcu_dereference(clear_flag(iter)->p.next);
 			if (unlikely(is_removed(next)))
 				goto gc_node;
 			if ((mode == ADD_UNIQUE || mode == ADD_REPLACE)
 			    && !is_dummy(next)
+			    && clear_flag(iter)->p.reverse_hash == node->p.reverse_hash
 			    && !ht->compare_fct(node->key, node->key_len,
 						clear_flag(iter)->key,
 						clear_flag(iter)->key_len)) {
@@ -924,7 +933,7 @@ struct cds_lfht_node *_cds_lfht_add(struct cds_lfht *ht,
 				return_node = NULL;
 			else	/* ADD_DEFAULT and ADD_UNIQUE */
 				return_node = node;
-			goto gc_end;
+			goto end;
 		}
 
 	replace:
@@ -946,10 +955,6 @@ struct cds_lfht_node *_cds_lfht_add(struct cds_lfht *ht,
 		(void) uatomic_cmpxchg(&iter_prev->p.next, iter, new_next);
 		/* retry */
 	}
-gc_end:
-	/* Garbage collect logically removed nodes in the bucket */
-	dummy_node = (struct cds_lfht_node *) lookup;
-	_cds_lfht_gc_bucket(dummy_node, node);
 end:
 	return return_node;
 }
@@ -1340,6 +1345,7 @@ void cds_lfht_lookup(struct cds_lfht *ht, void *key, size_t key_len,
 		next = rcu_dereference(node->p.next);
 		if (likely(!is_removed(next))
 		    && !is_dummy(next)
+		    && clear_flag(node)->p.reverse_hash == reverse_hash
 		    && likely(!ht->compare_fct(node->key, node->key_len, key, key_len))) {
 				break;
 		}