Re: [PATCH] kdevt-diff

[Linus Torvalds]

On Mon, 14 Apr 2003, Joel Becker wrote:
>
> On Mon, Apr 14, 2003 at 12:45:36AM +0200, [e-mail] wrote:
> > The structure here is 8+8, except when more bits are
> > present, in which case it is 16+16, except when more bits
> > are present, in which case it is 32+32.
> 
> 	Why complicate things?  Is it that bad?  We'd all have to know
> about the mess when dealing with userspace.

Well, the thing is, we absolutely _do_ need to have the 8+8 split, in
order to make old devices look the same old way for old binaries.

And the 32+32 split is what the new maximum would be, so ..

The 16+16 split is not strictly necessary, but Andries pointed out to me
that there are filesystems etc external storage that only support a 32-bit
opaque dev_t, so we'd need to marshall the device number _some_ way for
them anyway, and having a standard way to do that is better than having
everybody come up with their own variations.

(My prefernce for the 32-bit version would be 12+20 bits, but it's not a
very strong one, and it doesn't really matter for the kernel proper, so I
think Andries who has been tirelessly working on this for five years or
more gets the final say on it).

		Linus