Hi Dave:
You're absolutely right about there being a problem with the TSO packet
trimming code. The cause of this lies in the tcp_fragment() function.
When we allocate a fragment for a completely non-linear packet the
truesize is calculated for a payload length of zero. This means that
truesize could in fact be less than the real payload length.
When that happens the TSO packet trimming can cause truesize to become
negative. This in turn can cause sk_forward_alloc to be -n * PAGE_SIZE
which would trigger the warning.
I've copied the code you used in tso_fragment which should work here.
Signed-off-by: Herbert Xu <[EMAIL PROTECTED]>
Everyone who's having the sk_forward_alloc warning problem should give
this patch a go to see if it cures things.
Just in case this still doesn't fix it, could everyone please also verify
whether disabling SMP has any effect on reproducing this?
Thanks,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <[EMAIL PROTECTED]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index b871db6..44df1db 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -551,7 +551,9 @@
buff = sk_stream_alloc_skb(sk, nsize, GFP_ATOMIC);
if (buff == NULL)
return -ENOMEM; /* We'll just try again later. */
- sk_charge_skb(sk, buff);
+
+ buff->truesize = skb->len - len;
+ skb->truesize -= buff->truesize;
/* Correct the sequence numbers. */
TCP_SKB_CB(buff)->seq = TCP_SKB_CB(skb)->seq + len;
