openwrt/package/madwifi/patches/350-performance.patch

Index: madwifi-trunk-r3314/ath/if_ath.c
===================================================================
--- madwifi-trunk-r3314.orig/ath/if_ath.c	2008-04-17 02:56:31.000000000 +0200
+++ madwifi-trunk-r3314/ath/if_ath.c	2008-04-17 03:20:28.000000000 +0200
@@ -3237,7 +3237,6 @@
 	struct ath_softc *sc = dev->priv;
 	struct ieee80211_node *ni = NULL;
 	struct ath_buf *bf = NULL;
-	struct ether_header *eh;
 	ath_bufhead bf_head;
 	struct ath_buf *tbf, *tempbf;
 	struct sk_buff *tskb;
@@ -3249,6 +3248,7 @@
 	*/
 	int requeue = 0;
 #ifdef ATH_SUPERG_FF
+	struct ether_header *eh;
 	unsigned int pktlen;
 	struct ieee80211com *ic = &sc->sc_ic;
 	struct ath_node *an;
@@ -3314,27 +3314,9 @@
 		requeue = 1;
 		goto hardstart_fail;
 	}
-#endif
 
-	/* If the skb data is shared, we will copy it so we can strip padding
-	 * without affecting any other bridge ports. */
-	if (skb_cloned(skb)) {
-		/* Remember the original SKB so we can free up our references */
-		struct sk_buff *skb_new;
-		skb_new = skb_copy(skb, GFP_ATOMIC);
-		if (skb_new == NULL) {
-			DPRINTF(sc, ATH_DEBUG_XMIT,
-				"Dropping; skb_copy failure.\n");
-			/* No free RAM, do not requeue! */
-			goto hardstart_fail;
-		}
-		ieee80211_skb_copy_noderef(skb, skb_new);
-		ieee80211_dev_kfree_skb(&skb);
-		skb = skb_new;
-	}
 	eh = (struct ether_header *)skb->data;
 
-#ifdef ATH_SUPERG_FF
 	/* NB: use this lock to protect an->an_tx_ffbuf (and txq->axq_stageq)
 	 *     in athff_can_aggregate() call too. */
 	ATH_TXQ_LOCK_IRQ(txq);
Index: madwifi-trunk-r3314/net80211/ieee80211_output.c
===================================================================
--- madwifi-trunk-r3314.orig/net80211/ieee80211_output.c	2008-04-17 02:56:30.000000000 +0200
+++ madwifi-trunk-r3314/net80211/ieee80211_output.c	2008-04-17 04:29:06.000000000 +0200
@@ -615,100 +615,45 @@
 		skb = skb_unshare(skb, GFP_ATOMIC);
 	}
 
-#ifdef ATH_SUPERG_FF
-	if (isff) {
-		if (skb == NULL) {
+	if (skb_cloned(skb) ||
+		(need_headroom > skb_headroom(skb)) ||
+		(!isff && (need_tailroom > skb_tailroom(skb)))) {
+
+		if (pskb_expand_head(skb, need_headroom, need_tailroom, GFP_ATOMIC)) {
 			IEEE80211_DPRINTF(vap, IEEE80211_MSG_OUTPUT,
-				"%s: cannot unshare for encapsulation\n",
-				__func__);
+				"%s: cannot expand storage (tail)\n", __func__);
 			vap->iv_stats.is_tx_nobuf++;
-			ieee80211_dev_kfree_skb(&skb2);
-
+			ieee80211_dev_kfree_skb(&skb);
 			return NULL;
 		}
+	}
 
-		/* first skb header */
-		if (skb_headroom(skb) < need_headroom) {
-			struct sk_buff *tmp = skb;
-			skb = skb_realloc_headroom(skb, need_headroom);
-			if (skb == NULL) {
-				IEEE80211_DPRINTF(vap, IEEE80211_MSG_OUTPUT,
-					"%s: cannot expand storage (head1)\n",
-					__func__);
-				vap->iv_stats.is_tx_nobuf++;
-				ieee80211_dev_kfree_skb(&skb2);
-				return NULL;
-			} else
-				ieee80211_skb_copy_noderef(tmp, skb);
-			ieee80211_dev_kfree_skb(&tmp);
-			/* NB: cb[] area was copied, but not next ptr. must do that
-			 *     prior to return on success. */
+#ifdef ATH_SUPERG_FF
+	if (isff) {
+		if (skb_shared(skb2)) {
+			/* Take our own reference to the node in the clone */
+			ieee80211_ref_node(SKB_CB(skb2)->ni);
+			/* Unshare the node, decrementing users in the old skb */
+			skb2 = skb_unshare(skb2, GFP_ATOMIC);
 		}
 
-		/* second skb with header and tail adjustments possible */
-		if (skb_tailroom(skb2) < need_tailroom) {
-			int n = 0;
-			if (inter_headroom > skb_headroom(skb2))
-				n = inter_headroom - skb_headroom(skb2);
-			if (pskb_expand_head(skb2, n,
-			    need_tailroom - skb_tailroom(skb2), GFP_ATOMIC)) {
-				ieee80211_dev_kfree_skb(&skb2);
-				IEEE80211_DPRINTF(vap, IEEE80211_MSG_OUTPUT,
-					"%s: cannot expand storage (tail2)\n",
-					__func__);
-				vap->iv_stats.is_tx_nobuf++;
-				/* this shouldn't happen, but don't send first ff either */
-				ieee80211_dev_kfree_skb(&skb);
-			}
-		} else if (skb_headroom(skb2) < inter_headroom) {
-			struct sk_buff *tmp = skb2;
+		if ((skb_cloned(skb2) ||
+			(inter_headroom > skb_headroom(skb2)) ||
+			(need_tailroom > skb_tailroom(skb2)))) {
 
-			skb2 = skb_realloc_headroom(skb2, inter_headroom);
-			if (skb2 == NULL) {
+			if (pskb_expand_head(skb2, inter_headroom,
+				need_tailroom, GFP_ATOMIC)) {
 				IEEE80211_DPRINTF(vap, IEEE80211_MSG_OUTPUT,
-					"%s: cannot expand storage (head2)\n",
-					__func__);
+					"%s: cannot expand storage (tail)\n", __func__);
 				vap->iv_stats.is_tx_nobuf++;
-				/* this shouldn't happen, but don't send first ff either */
 				ieee80211_dev_kfree_skb(&skb);
-				skb = NULL;
-			} else
-				ieee80211_skb_copy_noderef(tmp, skb);
-			ieee80211_dev_kfree_skb(&tmp);
-		}
-		if (skb) {
-			skb->next = skb2;
+				ieee80211_dev_kfree_skb(&skb2);
+				return NULL;
+			}
 		}
-		return skb;
+		skb->next = skb2;
 	}
 #endif /* ATH_SUPERG_FF */
-	if (skb == NULL) {
-		IEEE80211_DPRINTF(vap, IEEE80211_MSG_OUTPUT,
-			"%s: cannot unshare for encapsulation\n", __func__);
-		vap->iv_stats.is_tx_nobuf++;
-	} else if (skb_tailroom(skb) < need_tailroom) {
-		int n = 0;
-		if (need_headroom > skb_headroom(skb))
-			n = need_headroom - skb_headroom(skb);
-		if (pskb_expand_head(skb, n, need_tailroom - 
-					skb_tailroom(skb), GFP_ATOMIC)) {
-			IEEE80211_DPRINTF(vap, IEEE80211_MSG_OUTPUT,
-				"%s: cannot expand storage (tail)\n", __func__);
-			vap->iv_stats.is_tx_nobuf++;
-			ieee80211_dev_kfree_skb(&skb);
-		}
-	} else if (skb_headroom(skb) < need_headroom) {
-		struct sk_buff *tmp = skb;
-		skb = skb_realloc_headroom(skb, need_headroom);
-		/* Increment reference count after copy */
-		if (skb == NULL) {
-			IEEE80211_DPRINTF(vap, IEEE80211_MSG_OUTPUT,
-				"%s: cannot expand storage (head)\n", __func__);
-			vap->iv_stats.is_tx_nobuf++;
-		} else
-			ieee80211_skb_copy_noderef(tmp, skb);
-		ieee80211_dev_kfree_skb(&tmp);
-	}
 
 	return skb;
 }