Re: 2.6.13-rc4 - kernel panic - BUG at net/ipv4/tcp_output.c:918

[Herbert Xu <herbert@gondor.apana.org.au>]

On Thu, Aug 04, 2005 at 01:33:29PM +1000, herbert wrote:
> 
> So I suppose we should reset cwnd_quota after tcp_transmit_skb?

Please try this patch to see if this is really the problem or not.

Thanks,
-- 
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diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1027,19 +1027,14 @@ static int tcp_write_xmit(struct sock *s
 		tcp_minshall_update(tp, mss_now, skb);
 		sent_pkts++;
 
-		/* Do not optimize this to use tso_segs. If we chopped up
-		 * the packet above, tso_segs will no longer be valid.
-		 */
-		cwnd_quota -= tcp_skb_pcount(skb);
-
-		BUG_ON(cwnd_quota < 0);
-		if (!cwnd_quota)
-			break;
-
 		skb = sk->sk_send_head;
 		if (!skb)
 			break;
+
 		tso_segs = tcp_init_tso_segs(sk, skb, mss_now);
+		cwnd_quota = tcp_cwnd_test(tp, skb);
+		if (!cwnd_quota)
+			break;
 	}
 
 	if (likely(sent_pkts)) {