Re: 2.4 tcp very slow under certain circumstances (Re: netdev issues (3c905B))

[Ookhoi <ookhoi@dds.nl>]

Hi David,

>  > We have exactly the same problem but in our case it depends on the
>  > following three conditions: 1, kernel 2.4 (2.2 is fine), 2, windows ip
>  > header compression turned on, 3, a free internet access provider in
>  > Holland called 'Wish' (which seemes to stand for 'I Wish I had a faster
>  > connection').
>  > If we remove one of the three conditions, the connection is oke. It is
>  > only tcp which is affected.
>  > A packet on its way from linux server to windows client seems to get
>  > dropped once and retransmitted. This makes the connection _very_ slow.
> 
> :-( I hate these buggy systems.
> 
> Does this patch below fix the performance problem and are the windows
> clients win2000 or win95?

It is 95 in our case. I'll test the patch today and report back to you.
Thanks a lot!

	Ookhoi


> --- include/net/ip.h.~1~	Mon Feb 19 00:12:31 2001
> +++ include/net/ip.h	Wed Feb 21 02:56:15 2001
> @@ -190,9 +190,11 @@
>  
>  static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst)
>  {
> +#if 0
>  	if (iph->frag_off&__constant_htons(IP_DF))
>  		iph->id = 0;
>  	else
> +#endif
>  		__ip_select_ident(iph, dst);
>  }
>