Re: userspace breakage

Adrian Bunk
2005-12-29T23:25:51Z

On Thu, Dec 29, 2005 at 02:56:16PM -0800, Linus Torvalds wrote:
>
> On Thu, 29 Dec 2005, Dave Jones wrote:
>...
> > Just a few years ago, if someone suggested breaking a userspace
> > app in a kernel upgrade, they'd be crucified on linux-kernel, now
> > it's 'the norm').
>
> That really isn't acceptable. Breaking user space - even things that are
> "close" to the kernel like udev scripts and alsa-lib, really is NOT a good
> idea.
>
> We're much better off wasting a bit of time on backwards compatibility,
> than wasting a lot of user time and irritation (and indirectly, developer
> time) on linkages to packages outside the kernel.
>
> If you cannot upgrade a kernel without ugrading some user package, that
> should be considered a real bug and a regression.
>
> There are real technical reasons for not allowing those kinds of version
> linkages: it makes it MUCH harder to blame the right thing when things go
> wrong.
>
> Now, I'm not saying that we can always support everything that goes on in
> user space forever, but dammit, we can try damn hard.
>...

Was it a mistake to drop support for ipfwadm and ipchains?
Was it a mistake to drop support for devsfs?
Will it be a mistake to drop support for gcc < 3.2?
Will it be a mistake to remove the obsolete raw driver?
Will it be a mistake to drop the Video4Linux API 1 ioctls?
Will it be a mistake to drop support for pcmcia-cs?
...

And if any of these was or will not be a mistake, when is the right time
for the userspace breakage?

I did agree with what you express before support for ipchains was
removed and support for devfs was removed, and many more I do not
remember currently, but I've now simply accepted that regarding kernel
development, 6 is an odd number.

The fundamental problem is that the current development model
contains no well-defined points where breakages of the kernel-related
userspace were allowed and expected by users.

> Linus

cu
Adrian

--

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"Only a promise," Lao Er said.
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