Todd Vierling <tv@NetBSD.ORG> writes:

> 
> The problem with the minor-split proposal you had was that it would require
> devices, once renumbered, to handle two different kinds of minor numbers. 

Excuse me?  It would require a conversion step for at least every
major number that has its minor number format changes -- just like the
plan you're talking about.  In this respect, there's no difference.

> - 16 bit dev_t's converted to 32 bit only when:
>   - storing in specinfo struct
>   - comparing in vfs_subr.c
>   - looking up hash values in SPECHASH()

You only have to do this once, before the device number is used
anywhere in checkalias().  The rest of these things all use the same
value.