lkml.org 
[lkml]   [2005]   [Aug]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: 2.6.13-rc4 - kernel panic - BUG at net/ipv4/tcp_output.c:918
From
On Mon, Aug 01, 2005 at 08:33:20AM +0000, Guillaume Pelat wrote:
>
> I just tried the patch attached. :)
>
> The bug is still here (same symptoms), with a slightly different backtrace :
> ------------[ cut here ]------------
> kernel BUG at net/ipv4/tcp_output.c:918!

OK, let's try again :)

I bet it's the tcp_enter_cwr() call in tcp_transmit_skb(). So
the sequence is:

tcp_write_xmit
cwnd_quota = tcp_cwnd_test
tcp_transmit_skb
tcp_enter_cwr
tp->snd_cwnd = min(tp->snd_cwnd, in_flight + 1)

At this point cwnd_quota is out-of-sync with tp->snd_cwnd.

cwnd_quota -= tcp_skb_pcount(skb)
cwnd_quota > 0
tcp_tso_should_defer
BUG since tp->snd_cwnd is smaller than what
cwnd_quota indicated.

So I suppose we should reset cwnd_quota after tcp_transmit_skb?

Perhaps we should only transmit one MSS in this case?

Cheers,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-08-04 05:37    [W:0.055 / U:0.300 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site