[ltt-dev] [PATCH 6/9] test hash value Confilict with buckets

[Lai Jiangshan]

Signed-off-by: Lai Jiangshan <laijs at cn.fujitsu.com>
---
 tests/test_urcu_hash.c |   20 +++++++++++++++++++-
 1 files changed, 19 insertions(+), 1 deletions(-)

diff --git a/tests/test_urcu_hash.c b/tests/test_urcu_hash.c
index 02d2c63..eb42522 100644
--- a/tests/test_urcu_hash.c
+++ b/tests/test_urcu_hash.c
@@ -141,6 +141,7 @@ static unsigned long min_hash_alloc_size = DEFAULT_MIN_ALLOC_SIZE;
 static unsigned long init_populate;
 static int opt_auto_resize;
 static int add_only, add_unique, add_replace;
+static int opt_test_bucket_conflict;
 
 static int count_pipe[2];
 
@@ -390,8 +391,22 @@ int lookup_first(struct cds_lfht_node *node, void *key)
 static inline
 void lfht_test_node_init(struct lfht_test_node *node)
 {
+	unsigned long hash = test_rand_get();
+
 	cds_lfht_node_init(&node->node);
-	node->hash = test_rand_get();
+
+	if (opt_test_bucket_conflict) {
+#if (CAA_BITS_PER_LONG == 32)
+		int hash_bits= test_rand_get_bits(5);
+#else
+		int hash_bits= test_rand_get_bits(6);
+#endif
+
+		if (hash_bits > 4)
+			hash &= (1UL << hash_bits) - 1;
+	}
+
+	node->hash = hash;
 }
 
 static
@@ -674,6 +689,7 @@ void show_usage(int argc, char **argv)
 	printf("        [-i] Add only (no removal).\n");
 	printf("        [-k nr_nodes] Number of nodes to insert initially.\n");
 	printf("        [-A] Automatically resize hash table.\n");
+	printf("	[-C] Use some hash value Confilict with buckets.\n");
 	printf("\n\n");
 }
 
@@ -792,6 +808,8 @@ int main(int argc, char **argv)
 		case 'A':
 			opt_auto_resize = 1;
 			break;
+		case 'C':
+			opt_test_bucket_conflict = 1;
 			break;
 
 		}
-- 
1.7.4.4