Re: SLUB: Return ZERO_SIZE_PTR for kmalloc(0)

From: Pavel Machek
Date: Wed Jun 06 2007 - 17:34:59 EST


Hi!

> >>No, what we have is a sizeof(pointer) sized pointer
> >>pointing to an
> >>object of size zero. ZERO_SIZE_PTR is butt-ugly. With
> >>a really ugly butt.
> >
> >It doesn't matter. It will never, ever, be used by
> >anything except the
> >kmalloc internals. No client code should ever use the
> >constant for
> >anything.
>
> Yes, I'm aware of this (I should snip less) but I still
> feel it's not a good name. When I read say "a 64-bit
> pointer" I immediately take that to mean a pointer of
> size 64-bit, not a pointer to 64-bits and only it not
> making any sense would stop me from interpreting
> "ZERO_SIZE_PTR" similarly.
>
> Yes, it's internal but given that this is open-source
> which, optimistically, is read many more times than it's
> written one should still strive for code that reads nice
> as far as I'm concerned. It's obviously also not hugely
> important but it's just that ZERO_SIZE_PTR makes my neck
> hair stand up.

PTR_TO_NOTHING?
PTR_TO_0BYTES?
PTR_TO_0SIZE?
PTR_TO_ZERO_SIZE?
NOT_QUITE_NULL? :-)
FULL?
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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