Subject: Re: 32 bit dev_t
To: Charles M. Hannum <>
From: Chris G. Demetriou <>
List: tech-kern
Date: 01/13/1998 09:29:26
> * As an alternative to renumbering, you could instead make the minor
> number non-contiguous; i.e.:
>     3322222222221111111111
>     10987654321098765432109876543210
>     |--minor---||--major---||minor-|    new
>                     |major-||minor-|    old
> * Given the above scheme, should we decide to renumber everything at
> some point (hopefully only once!!!), we can simply choose some portion
> of the major numbers (say, the first 256) and use them for
> `compatibility'.  There's no need to waste half the number space.

So, I don't particularly like this because it makes device nodes much
harder to 'read' as hex numbers, and it also means that our device
nodes will look like those of no other system that i'm aware of.

Neither of those are hard, technical objections.

Also, if we're going to go to the trouble of making any change at all,
I _do_ think it would be a good time to do the renumbering.  (If we're
going to renumber, why make the device nodes ugly, too?)

Finally, as has been pointed out before, the most recent version of
the proposal wasted only _one_ new major number (0), out of 1024, for
backward compatibility.  8-)