From: Krishna Kumar <krkumar2@in.ibm.com>
Date: Wed, 9 Dec 2009 20:59:58 +0000 (+0000)
Subject: net: release dst entry while cache-hot for GSO case too
X-Git-Tag: firefly_0821_release~9833^2~3055^2~716
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=068a2de57ddf4f4;p=firefly-linux-kernel-4.4.55.git

net: release dst entry while cache-hot for GSO case too

Non-GSO code drops dst entry for performance reasons, but
the same is missing for GSO code. Drop dst while cache-hot
for GSO case too.

Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/core/dev.c b/net/core/dev.c
index be9924f60ec3..a8d68cdedbbe 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1853,6 +1853,14 @@ gso:
 
 		skb->next = nskb->next;
 		nskb->next = NULL;
+
+		/*
+		 * If device doesnt need nskb->dst, release it right now while
+		 * its hot in this cpu cache
+		 */
+		if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
+			skb_dst_drop(nskb);
+
 		rc = ops->ndo_start_xmit(nskb, dev);
 		if (unlikely(rc != NETDEV_TX_OK)) {
 			if (rc & ~NETDEV_TX_MASK)