Subject: Re: wrap up of pipe(2)
To: NetBSD Userlevel Technical Discussion List <tech-userlevel@NetBSD.ORG>
From: Greg A. Woods <>
List: tech-userlevel
Date: 10/14/2001 17:38:41
[ On Sunday, October 14, 2001 at 16:41:39 (-0400), der Mouse wrote: ]
> Subject: Re: wrap up of pipe(2)
> > [W]hat I really intended to imply there was a desire for the level of
> > detail afforded by a well worded standards document, for example --
> Except that that's what you say below you *don't* want.

No, that's what I _do_ want.  I desire my system's documentation have
the level of detail, and careful wording, of standards documents.

What I do not want is the system documentation to be as non-specific
w.r.t. implementation details as most standards docuemnts are.

It is of course OK though if the system documentation also notes how the
implementation differs from other common implementations or standards.

More is better (to a point anyway), but of course one cannot expect a
specific vendor's systems documentation to cover all the details of
other vendor's implementations, especially not when that vendor is a
non-profit volunteer-driven group.

> >> The only stuff that should be documented are the parts you can rely
> >> on, stuff that won't just change on someone's whim.
> > No thanks!  That just won't do.
> But that's exactly what a well worded standards document will give you:

Exactly, and I know where to find such documents when I need them.  :-)

When I want implementation specific descriptions I hope to find them in
the system's, and indeed the specific release's, documentation.

There is simply no point to maintaining systems documentation if it says
nothing more specific about the implementation than other commonly
available generic guides and/or standards documents say.

> Documentation on which of the possible alternative is chosen is, I
> believe, not appropriate for a manpage.  UTSL for that.

The source is handy, to be sure, but it is not an altnerative to good
systems documentation that accurately describes the implementation
details.  I.e. I expect to find implementation specific descriptions in
the systems documentation.

> > If I cannot ever receive an EFAULT from pipe(2) on even just one
> > architecture then I want the manual page to clearly document that
> > fact.
> Why?  It's not a part of the interface you can depend on.

But on a given platform, it sure as heck is!

> Which platform allows a user process to have more than half a moby of
> address space?  I can't think of any offhand (but admittedly am not
> familiar with more than about 5-10 of them).

I don't know for sure, but I don't know a lot about the VM limits either.

There are certainly modern machines which can address that much and more
physical memory, albiet only 64-bit machines IIRC, and if I'm not
mistaken sizeof(int) == 8 on NetBSD on all of them.....

							Greg A. Woods

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