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SubjectRe: PROPOSAL: /proc/dev
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....

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