svn commit: r217018 - stable/8/sys/netinet

[John Baldwin]

On Friday, January 07, 2011 4:36:38 am Bjoern A. Zeeb wrote:
> On Fri, 7 Jan 2011, Lawrence Stewart wrote:
> 
> > Hi George,
> >
> > On 01/06/11 05:52, George V. Neville-Neil wrote:
> >> Author: gnn
> >> Date: Wed Jan  5 18:52:30 2011
> >> New Revision: 217018
> >> URL: http://svn.freebsd.org/changeset/base/217018
> >>
> >> Log:
> >>   Fix binary compatability for netstats across the -x/-T changes
> >>   that have been previously MFC'd.
> >>
> >>   Reviewed by:	rwatson, bz
> >>
> >> Modified:
> >>   stable/8/sys/netinet/tcp_var.h
> >>
> ...
> >
> > On my stable/8 machine after updating world but not kernel I see "struct
> > xtcpcb size mismatch" messages which indicates the ABI has been futzed 
with.
> 
> Be sure that it's not local changes.
> 
> > Looking at the above diff I think this commit does indeed change the ABI
> > and therefore needs to be tweaked in order to maintain our current ABI
> > preservation policy for stable branches (unless I'm missing something?).
> > If the change to the ABI is intentional, a note in UPDATING would
> > probably be warranted.
> 
> I think you are missing that that was the "repair" commit.  Are you
> sure you didn't pickup the wrong versions?  There was about a 1 day
> timeframe, where things were hosed but I believe George fixed them
> all.
> 
> Hmm looking at the diff committed more closely I see that the two
> uint64_t are not were they should be.  Are you by any chance on i386
> or another 32bit platform?
> 
>  	uint64_t	t_sndrexmitpack;/* retransmit packets sent */
>  	uint64_t	t_rcvoopack;	/* out-of-order packets received */
> should move  after t_pspare2[6] and the patch I had seen had that.
> 
> Maybe we should even move them after _pad[] to keep the spares
> together.
> 
> Can you test this one?
> http://people.freebsd.org/~bz/20110107-01-restore-xtcpcb-ABI.diff

I think something like this is appropriate even regardless as it is cleaner to 
use the pad[] spots where they were originally.

-- 
John Baldwin