Subject: Re: Wart in tcp_output(), IPv6-related?
To: None <>
From: Jason R Thorpe <>
List: tech-net
Date: 04/26/2002 18:10:35
On Sat, Apr 27, 2002 at 09:07:30AM +0900, wrote:

 > 	because when I checked MHLEN can be smaller than 100 bytes on some arch,
 > 	and we may not be able to fit IPv4/v6 and TCP header/option into a
 > 	single M_PKTHDR mbuf.  they need to fit into a single mbuf due to
 > 	the assumption made near line 830.

Hm.  At this point, MSIZE is 256 on all platforms, so MHLEN should be
large enough everywhere.

 > 	so, we at least preserve the following "max_linkhdr + hdrlen > MHLEN"
 > 	condition.

Ok, I'll add another counter for that, too.

 > 	i am happy to remove "max_linkhdr + hdrlen + len <= MCLBYTES" line.
 > 	if the line gets removed the "always-copy" behavior will go away.

Yah, that's pretty much right.

        -- Jason R. Thorpe <>