Subject: Re: Is fdesc useful?
To: None <tech-kern@netbsd.org>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
List: tech-kern
Date: 04/02/2002 09:43:13
> what is the intended application of fdescfs?

"mount -o union -t fdesc /dev", near as I can figure.  When I use it,
that's how.

> I've never used it on any machine and I don't seem to miss it so far.
> I'd prefer to just sack the thing, rather than continue supporting
> it.

> Would anyone miss fdescfs if it [were] gone?

I would, for what that may be worth.  I consider it a significantly
more elegant way to support /dev/fd than tons of special devices,
especially since without fdesc you have to either restrict /dev/fd to
relatively low file descriptors or else create hundreds or thousands of
entries in it to cover all possible descriptors.  I have machines whose
rlimit.descriptors.hard is 1772; I really would rather not have 1772
entries in /dev/fd.  And aesthetically, I've never liked the kludge of
a special device driver whose open routine arranges to provoke hacks in
high kernel to do dups instead.

Besides, fdesc makes find(1)s on /dev much more interesting. :-)

I suspect, though, that for most (*most*) practical purposes, using
special devices and having 32 or 64 or some such number of them in
/dev/fd is enough.

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