Re: >256 ptys (previous subject line was garbage)
Jakub Jelinek (jj@sunsite.ms.mff.cuni.cz)
Fri, 5 Jun 1998 13:24:35 +0200 (MET DST)
>
> tytso@mit.edu writes:
> > Date: Mon, 1 Jun 1998 14:56:12 +1000
> > From: Richard Gooch <Richard.Gooch@atnf.CSIRO.AU>
> >
> > > Isn't the devfs supposed to allow major/minor-less devices? I seem to
> > > recall that for some devices major/minor number were used anywas since
> > > userland code used it (mounted filesystems e.g.). For ptys this should be
> > > no problem.
> >
> > Devfs does allows major/minor-less devices. You could hack the tty
> > driver to make use of this. Check out the devfs FAQ at:
> > http://www.atnf.csiro.au/~rgooch/linux/devfs.txt
> >
> > This is actually a bad thing, since there's been a lot of talk about
> > using major/minor numbers as part of a tty locking scheme.
>
> Well, you don't actually *have* to get rid of major/minor
> numbers. Devfs also allows you to have automatic allocation of device
> numbers as well as supporting normal hard-wired major/minor numbers.
> In the devfs FAQ I propose automatic device number allocation for SCSI
> and tty devices. This would give us up to 64k SCSI partitions and tty
> devices without breaking userspace.
>
> BTW: what is this tty locking scheme?
When most of the systems use glibc at the moment, I think there is no need
for major/minor-less devices: even glibc2.0 has u_quad_t dev_t, that is
64bits... So, the only thing one has to update is glibc to make use of huge
device numbers, while keeping locking schemes work, fdisk knowing block
major 8 is SCSI, etc.
Cheers,
Jakub
___________________________________________________________________
Jakub Jelinek | jj@sunsite.mff.cuni.cz | http://sunsite.mff.cuni.cz
Administrator of SunSITE Czech Republic, MFF, Charles University
___________________________________________________________________
Ultralinux - first 64bit OS to take full power of the UltraSparc
Linux version 2.1.103 on a sparc64 machine (498.80 BogoMips).
___________________________________________________________________
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu