Commit 46c749ea authored Dec 08, 2015 by Herbert Xu Committed by David S. Miller Dec 08, 2015

rhashtable: Remove unnecessary wmb for future_tbl



The patch 9497df88 ("rhashtable:
Fix reader/rehash race") added a pair of barriers.  In fact the
wmb is superfluous because every subsequent write to the old or
new hash table uses rcu_assign_pointer, which itself carriers a
full barrier prior to the assignment.

Therefore we may remove the explicit wmb.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent bc22ff53

lib/rhashtable.c

+0 −3

Original line number	Diff line number	Diff line
		@@ -231,9 +231,6 @@ static int rhashtable_rehash_attach(struct rhashtable *ht,
		*/
		rcu_assign_pointer(old_tbl->future_tbl, new_tbl);

		/* Ensure the new table is visible to readers. */
		smp_wmb();

		spin_unlock_bh(old_tbl->locks);

		return 0;