Re: userspace breakage

[Adrian Bunk <bunk@stusta.de>]

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

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed