Re: vm_page_t related KBI [Was: Re: panic at vm_page_wire with FreeBSD 9.0 Beta 3]

From: Kostik Belousov <kostikbel_at_gmail.com>
Date: Sun, 6 Nov 2011 18:42:04 +0200
On Sun, Nov 06, 2011 at 07:22:51AM -0800, mdf_at_freebsd.org wrote:
> On Sun, Nov 6, 2011 at 4:43 AM, Kostik Belousov <kostikbel_at_gmail.com> wrote:
> > Regarding the _vm_page_lock() vs. vm_page_lock_func(), the mutex.h has
> > a lot of violations in regard of the namespaces, IMO. The __* namespace
> > is reserved for the language implementation, so our freestanding program
> > (kernel) ignores the requirements of the C standard with the names like
> > __mtx_lock_spin(). Using the name _vm_page_lock() is valid, but makes
> > it not unreasonable for other developers to introduce reserved names.
> > So I decided to use the suffixes. vm_map.h locking is free of these
> > violations.
> 
> I'm pretty sure that when the C standard says, "the implementation",
> they're referring to the compiler and OS it runs on.  Which makes the
> FreeBSD kernel part of "the implementation", which is precisely why so
> many headers have defines that start with __ and then, if certain
> posix defines are set, also uses non-__ versions of the name.

For libc providing parts, required by standard, you are right.
But our kernel is a freestanding program using a compiler, so in-kernel
uses of the reserved namespace is a violation.

Received on Sun Nov 06 2011 - 15:42:08 UTC

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