From: Felix Fietkau <nbd@openwrt.org>
Date: Sat, 18 Dec 2010 18:30:49 +0000 (+0100)
Subject: mac80211: skip unnecessary pskb_expand_head calls
X-Git-Tag: v2.6.38-rc1~476^2~14^2~3^2~84
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4cd06a344db752f513437138953af191cbe9a691;p=platform%2Fkernel%2Flinux-3.10.git

mac80211: skip unnecessary pskb_expand_head calls

If the skb is not cloned and we don't need any extra headroom, there
is no point in reallocating the skb head.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 8d01d21..90ee235 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1546,8 +1546,10 @@ static int ieee80211_skb_resize(struct ieee80211_local *local,
 
 	if (skb_header_cloned(skb))
 		I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
-	else
+	else if (head_need || tail_need)
 		I802_DEBUG_INC(local->tx_expand_skb_head);
+	else
+		return 0;
 
 	if (pskb_expand_head(skb, head_need, tail_need, GFP_ATOMIC)) {
 		wiphy_debug(local->hw.wiphy,