netdev - [PATCH net-next v2 3/3] net: bridge: fdb: restore unlikely() when taking over externally added entries

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Message-Id: <20191101124639.32140-4-nikolay@cumulusnetworks.com>
Date:   Fri,  1 Nov 2019 14:46:39 +0200
From:   Nikolay Aleksandrov <nikolay@...ulusnetworks.com>
To:     netdev@...r.kernel.org
Cc:     roopa@...ulusnetworks.com, bridge@...ts.linux-foundation.org,
        davem@...emloft.net,
        Nikolay Aleksandrov <nikolay@...ulusnetworks.com>
Subject: [PATCH net-next v2 3/3] net: bridge: fdb: restore unlikely() when taking over externally added entries

Taking over hw-learned entries is not a likely scenario so restore the
unlikely() use for the case of SW taking over externally learned
entries.

Signed-off-by: Nikolay Aleksandrov <nikolay@...ulusnetworks.com>
---
 net/bridge/br_fdb.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index 7500c84fc675..284b3662d234 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -587,8 +587,10 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 				fdb->dst = source;
 				fdb_modified = true;
 				/* Take over HW learned entry */
-				test_and_clear_bit(BR_FDB_ADDED_BY_EXT_LEARN,
-						   &fdb->flags);
+				if (unlikely(test_bit(BR_FDB_ADDED_BY_EXT_LEARN,
+						      &fdb->flags)))
+					clear_bit(BR_FDB_ADDED_BY_EXT_LEARN,
+						  &fdb->flags);
 			}
 			if (now != fdb->updated)
 				fdb->updated = now;
-- 
2.21.0