Re: starting with 2.7

[Willy Tarreau <willy@w.ods.org>]

On Sun, Jan 02, 2005 at 05:19:35PM -0800, William Lee Irwin III wrote:
> On Sun, Jan 02, 2005 at 04:30:11PM -0800, William Lee Irwin III wrote:
> >> The presumption is that these changes are frivolous. This is false.
> >> The removals of these features are motivated by their unsoundness,
> >> and those removals resolve real problems. If they did not do so, they
> >> would not pass peer review.
> 
> On Mon, Jan 03, 2005 at 01:45:51AM +0100, Adrian Bunk wrote:
> > The netfilter people plan to remove ipfwadm and ipchains before 2.6.11 .
> > This is legacy code that makes their development sometimes a bit harder, 
> > but AFAIK ipchains in 2.6.10 doesn't suffer from any serious real 
> > problems.
> 
> They're superseded by iptables and their sole uses are by the Linux-
> specific applications to manipulate this privileged aspect of system
> state. This makes a much weaker case for backward compatibility than
> general nonprivileged standardized system calls.

That's not the problem. There was a feature freeze by which everything which
was considered hard to maintain or not very stable should have been removed.
When 2.6 was announced, it was with a set of features. Who know, perhaps there
are a few people who could replace a kernel 2.0 by a 2.6 on some firewalls.
Even if they are only 2 or 3 people, there is no reason that suddenly a feature
should be removed in the stable series. But it should be removed in 2.7 if it's
a nightmare to maintain.

If the motivation to break backwards compatibility is not enough anymore to
justify development kernels, I don't know what will justify it anymore.
I'm particularly fed up by some developer's attitude who seem to never go
outside and see how their creations are used by people who really trust the
"stable" term... until they realize that this word is used only for marketting,
eg. help distro makers announce their new major release at the right moment.
ipfwadm had about 2 years to be removed before 2.6, wasn't that enough ? Once
the stable release is out, the developer's point of view about how is creation
*might* be used is not a justification to remove it. But of course, his
difficulties at maintaining the code is fairly enough for him to say "well, it
was a mistake to enable this, I don't want it in the future version anymore".

Why do you think that so many people are still using 2.4 (and even older
versions) ? This is because they are the only ones who don't constantly
change under your feet and from which you can build something reliable and
guaranteed maintainable. At least, I've not seen any commercial product based
on 2.6 yet !

Please, stop constantly changing the contents of the "stable" kernel.
 
> On Mon, Jan 03, 2005 at 01:45:51AM +0100, Adrian Bunk wrote:
> > My impression is that currently 2.4 doesn't take that much time of 
> > developers (except for Marcelo's), and that it's a quite usable and 
> > stable kernel.
> 
> The ``stable'' moniker and distros being based on 2.4 are horrors
> beyond imagination and developers are pushed to in turn push
> inappropriate features on 2.4.x and maintain them out-of-tree for
> 2.4.x

I clearly don't agree with you, for a simple reason : those out-of-tree
features will always be, because each distro likes to add a few features,
like SquashFS, PaX, etc... And indeed, that's one of the reasons I *stay*
on 2.4. It's so simple to simply upgrade the kernel, patch and recompile
without spending days complaining "grrr... why did they change this ?".
As soon as you have at least *ONE* patch to apply to a kernel for your
distro, 2.4 is a safer bet than 2.6 if you don't want to restart everything
at each minor release. The 2.4 kernel is more what I consider stable than
2.6, eventhough it's not totally. 2.0 and 2.2 *are* stable, because I'm
certain that every future releases will only be bugfixes and will touch
only a few lines.

At the moment, the only "serious" use I've found for a 2.6 is a kexec-based
bootloader for known hardware. I've already seen that maintaining it up to
date is not simple, I wonder how distro people work with it... I wouldn't
have to do their work right now.

Regards,
Willy