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rhashtable: Remove unnecessary wmb for future_tbl 

The patch 9497df88ab ("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>
This commit is contained in:
Herbert Xu 2015-12-08 17:09:04 +08:00 committed by David S. Miller
parent bc22ff5363
commit 46c749eac9
1 changed files with 0 additions and 3 deletions
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3
lib/rhashtable.c
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@ -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;