Le vendredi 25 février 2011 à 15:35 -0600, Ajit Khaparde a écrit :

I asked that because, if a switch is part a of the configuration,
the ASIC can receive packets other than the tcp flow.

And if hashing is enabled for IP packets, we can see this behavior.
The other values indicate that hashing has been enabled for IPv4 packets.

To make sure RSS (and rxhash) was OK, I added following debugging aid :

diff --git a/include/net/sock.h b/include/net/sock.h
index da0534d..e9b1180 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h

@@ -688,6 +688,7 @@ static inline void sock_rps_save_rxhash(struct sock *sk, u32 rxhash)
 {
 #ifdef CONFIG_RPS
 	if (unlikely(sk->sk_rxhash != rxhash)) {
+		pr_err("rxhash change from %x to %x\n", sk->sk_rxhash, rxhash);
 		sock_rps_reset_flow(sk);
 		sk->sk_rxhash = rxhash;
 	}

And got following traces :

[  201.170297] change rxhash from 0 to be0b5a87
[  232.607474] bonding: bond1: Setting eth3 as active slave.
[  232.607478] bonding: bond1: making interface eth3 the new active one.
[  232.710848] change rxhash from be0b5a87 to e56a3c1e
[  300.047500] bonding: bond1: Setting eth1 as active slave.
[  300.047504] bonding: bond1: making interface eth1 the new active one.
[  300.159162] change rxhash from e56a3c1e to be0b5a87

The flip occured when I changed my active slave (bonding mode=1).

eth1 is a bnx2 NIC, while eth3 a be2net one, so its OK to change the rxhash in this case 
(different firmware/algo)

So as far as be2net is concerned, everything seems OK : all packets for 
a given flow get an unique RSS hash and can feed skb->rxhash