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From: Andi Kleen <andi@firstfloor•org>
To: davem@davemloft•net
Cc: netdev@vger•kernel.org
Subject: [PATCH] Make simple TX hash little endian safe.
Date: Mon, 21 Jul 2008 10:48:07 +0200	[thread overview]
Message-ID: <1216630088-10328-1-git-send-email-andi@firstfloor.org> (raw)

From: Andi Kleen <andi@basil•nowhere.org>

Currently it will not use the lower
bits at all on big endian system, mapping e.g. all connections to a single
queue on a local network which only differs in the low bits.

Also fold the upper 16 bits always in the lower 16bits.

Signed-off-by: Andi Kleen <ak@linux•intel.com>
---
 net/core/dev.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index 2eed17b..c35fefc 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1694,8 +1694,11 @@ static u16 simple_tx_hash(struct net_device *dev, struct sk_buff *skb)
 	ports = (u32 *) (skb_network_header(skb) + (ihl * 4));
 
 	hash = 0;
-	while (alen--)
-		hash ^= *addr++;
+	while (alen--) {
+		hash ^= ntohl(*addr); 
+		addr++;
+	}
+	hash ^= hash >> 16; /* More folding needed? */
 
 	switch (ip_proto) {
 	case IPPROTO_TCP:
-- 
1.5.6


             reply	other threads:[~2008-07-21  8:48 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-07-21  8:48 Andi Kleen [this message]
2008-07-21  8:48 ` [PATCH] Add a statistics counter for tx hash miss Andi Kleen
2008-07-21 16:33   ` David Miller
2008-07-21 16:44     ` Andi Kleen
2008-07-21 16:51       ` David Miller
2008-07-21 12:32 ` [PATCH] Make simple TX hash little endian safe Jarek Poplawski
2008-07-21 15:17   ` Andi Kleen
2008-07-21 16:44 ` David Miller
2008-07-21 17:20   ` Andi Kleen

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