Re: PROPOSAL: /proc/dev

[Richard Gooch]

H. Peter Anvin writes:
> > Why not?  If you could give us some good reasons why not then we probably
> > will drop it.  But several times, I have heard this come up, and never a
> > good reason why it shouldn't be done.  The two reasons that I have heard are:
> > 1)  Memory usage -- so if you can't spare the memory, don't use it!
> > 2)  Lack of user configurablity (IE different permissions, different names)
> >     -- so we have callbacks through a userspace daemon.  Or we let people
> >     write really simple kernelspace modules.  (Basicly a big select and a
> >     function call or three with constant arguments for each case.)
> 
> These are the arguments the proponents shoot down constantly, but they
> never address any of the REAL (IMO) problems (although the kernel
> space usage is likely to be prohibitive if done anything remotely like
> correctly.)  YOU REALLY DON'T WANT CALLBACKS -- if you do, then your
> device performance and reliability is going straight into the toilet.

We already have callbacks for the f_ops. So this scheme will increase
the callback depth by one. Is that really a big deal? We're only
talking about a handfull of cycles or so. I'm sure the syscall
overhead is much greater.

> At some point I'll probably get my act together and write an FAQ on
> this.  I'm sick and tired of rehashing the same argument every four
> months for about four years now...

Jeez, take it easy. I'm just trying to be constructive.

				Regards,

					Richard....