[ltt-dev] [PATCH 2/2] rculfhash: simplify BUCKET_FLAG tracking

[Lai Jiangshan]

Signed-off-by: Lai Jiangshan <laijs at cn.fujitsu.com>
---
 rculfhash.c |   41 ++++++++++++++++-------------------------
 1 files changed, 16 insertions(+), 25 deletions(-)

diff --git a/rculfhash.c b/rculfhash.c
index 88079f9..0163a1b 100644
--- a/rculfhash.c
+++ b/rculfhash.c
@@ -316,13 +316,6 @@ struct partition_resize_work {
 		    unsigned long start, unsigned long len);
 };
 
-static
-void _cds_lfht_add(struct cds_lfht *ht,
-		unsigned long size,
-		struct cds_lfht_node *node,
-		struct cds_lfht_iter *unique_ret,
-		int bucket);
-
 /*
  * Algorithm to reverse bits in a word by lookup table, extended to
  * 64-bit words.
@@ -728,6 +721,14 @@ struct cds_lfht_node *flag_bucket(struct cds_lfht_node *node)
 }
 
 static
+struct cds_lfht_node *flag_keep_bucket(struct cds_lfht_node *node,
+		unsigned long bucket)
+{
+	return (struct cds_lfht_node *) (((unsigned long) node) |
+			(bucket & BUCKET_FLAG));
+}
+
+static
 struct cds_lfht_node *get_end(void)
 {
 	return (struct cds_lfht_node *) END_VALUE;
@@ -815,10 +816,7 @@ void _cds_lfht_gc_bucket(struct cds_lfht_node *bucket, struct cds_lfht_node *nod
 			iter = next;
 		}
 		assert(!is_removed(iter));
-		if (is_bucket(iter))
-			new_next = flag_bucket(clear_flag(next));
-		else
-			new_next = clear_flag(next);
+		new_next = flag_keep_bucket(clear_flag(next), (unsigned long)iter);
 		(void) uatomic_cmpxchg(&iter_prev->next, iter, new_next);
 	}
 	return;
@@ -884,13 +882,15 @@ int _cds_lfht_replace(struct cds_lfht *ht, unsigned long size,
 /*
  * A non-NULL unique_ret pointer uses the "add unique" (or uniquify) add
  * mode. A NULL unique_ret allows creation of duplicate keys.
+ *
+ * @bucket_flag should be 0 or BUCKET_FLAG
  */
 static
 void _cds_lfht_add(struct cds_lfht *ht,
 		unsigned long size,
 		struct cds_lfht_node *node,
 		struct cds_lfht_iter *unique_ret,
-		int bucket_flag)
+		unsigned long bucket_flag)
 {
 	struct cds_lfht_node *iter_prev, *iter, *next, *new_node, *new_next,
 			*return_node;
@@ -960,14 +960,8 @@ void _cds_lfht_add(struct cds_lfht *ht,
 		assert(!is_removed(iter_prev));
 		assert(!is_removed(iter));
 		assert(iter_prev != node);
-		if (!bucket_flag)
-			node->next = clear_flag(iter);
-		else
-			node->next = flag_bucket(clear_flag(iter));
-		if (is_bucket(iter))
-			new_node = flag_bucket(node);
-		else
-			new_node = node;
+		node->next = flag_keep_bucket(clear_flag(iter), bucket_flag);
+		new_node = flag_keep_bucket(node, (unsigned long)iter);
 		if (uatomic_cmpxchg(&iter_prev->next, iter,
 				    new_node) != iter) {
 			continue;	/* retry */
@@ -978,10 +972,7 @@ void _cds_lfht_add(struct cds_lfht *ht,
 
 	gc_node:
 		assert(!is_removed(iter));
-		if (is_bucket(iter))
-			new_next = flag_bucket(clear_flag(next));
-		else
-			new_next = clear_flag(next);
+		new_next = flag_keep_bucket(clear_flag(next), (unsigned long)iter);
 		(void) uatomic_cmpxchg(&iter_prev->next, iter, new_next);
 		/* retry */
 	}
@@ -1113,7 +1104,7 @@ void init_table_populate_partition(struct cds_lfht *ht, unsigned long i,
 		new_node->reverse_hash =
 				bit_reverse_ulong((1UL << (i - 1)) + j);
 		_cds_lfht_add(ht, 1UL << (i - 1),
-				new_node, NULL, 1);
+				new_node, NULL, BUCKET_FLAG);
 	}
 	ht->cds_lfht_rcu_read_unlock();
 }
-- 
1.7.4.4