From 05e8689c9a3a208bf75b60662778d81e23eac460 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Sun, 1 Nov 2009 19:45:16 +0000
Subject: [PATCH] ifb: RCU locking avoids touching dev refcount
Avoids touching dev refcount in hotpath
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
drivers/net/ifb.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c
index 030913f8bd26..69c25668dd63 100644
--- a/drivers/net/ifb.c
+++ b/drivers/net/ifb.c
@@ -98,13 +98,15 @@ static void ri_tasklet(unsigned long dev)
stats->tx_packets++;
stats->tx_bytes +=skb->len;
- skb->dev = dev_get_by_index(&init_net, skb->iif);
+ rcu_read_lock();
+ skb->dev = dev_get_by_index_rcu(&init_net, skb->iif);
if (!skb->dev) {
+ rcu_read_unlock();
dev_kfree_skb(skb);
stats->tx_dropped++;
break;
}
- dev_put(skb->dev);
+ rcu_read_unlock();
skb->iif = _dev->ifindex;
if (from & AT_EGRESS) {
--
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