M> Aaron T Porter wrote:
>>
>> On Wed, 6 Oct 1999, Martin Dalecki wrote:
>>
>> > > OK, I'll bite. Gimme 1024 serial ports. Yesterday.
>> > > That is 2048 devices (standard).
>> > > Easy with devfs, pretty convoluted with dynamic major numbers.
>> >
>> > ? This is an academic exercise. You are not going to tell there is such
>> > a box
>> > out there? BTW if you didn't hear it before /dev/cuxx's are obsolete.
>>
>> I've seen (and used) SGI Origin boxes with hundreds (I admin'ed a
>> 512 serial port box), and I'm fairly certain one of the boxes had
>> an even 1024.
M> I'm scared! But let me guess it was all running fine withouth devfs
M> but with longer dev_t?
IRIX has had a devfs-like thing since the Origin came out (IRIX
6.4). It's a hybrid system, with physical devices created
dynamically under /hw, and /dev contains links to the physical
devices, and "regular" device files for software devices (ptys,
etc). dev_t is uint32_t. A program (ioconfig) runs at boot time to
fix /dev to match changes in /hw, and to set permissions to allow
non-root access. MAKEDEV is much reduced... Drivers for physical
devices don't *have* to use /hw, but they fit in a lot better.
This mechanism has been working successfully (with few bugs that I
am aware of), and shipping, for >3 years. It runs on "desktops to
supercomputers", though it was designed for the needs of the bigger
boxen.
-- Scott Henry <scotth@sgi.com> / Help! My disclaimer is missing! IRIX MTS, / GIGO *really* means: Garbage in, Gospel Out Silicon Graphics, Inc / http://reality.sgi.com/scotth/- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/