rhashtable: Free bucket tables asynchronously after rehash
There is in fact no need to wait for an RCU grace period in the
rehash function, since all insertions are guaranteed to go into
the new table through spin locks.
This patch uses call_rcu to free the old/rehashed table at our
leisure.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index e55bbc8..36fb091 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -141,6 +141,11 @@
kvfree(tbl);
}
+static void bucket_table_free_rcu(struct rcu_head *head)
+{
+ bucket_table_free(container_of(head, struct bucket_table, rcu));
+}
+
static struct bucket_table *bucket_table_alloc(struct rhashtable *ht,
size_t nbuckets)
{
@@ -288,9 +293,7 @@
* table, and thus no references to the old table will
* remain.
*/
- synchronize_rcu();
-
- bucket_table_free(old_tbl);
+ call_rcu(&old_tbl->rcu, bucket_table_free_rcu);
}
/**