why is it called "asm-generic/atomic.h"?

why is it called "asm-generic/atomic.h"?

[Robert P. J. Day]

  i'm just curious -- why does that particular header file have that
name?  its opening comment reads:

 * Allows to provide arch independent atomic definitions without the need to
 * edit all arch specific atomic.h files.

but that's *not* what that header file does.  rather, it simply
defines the "long" form of the atomic operations that can be used *in
addition to* the arch-specific ones.

  wouldn't it make more sense to have called that header file
something like "asm-generic/atomic_long.h", so as not to mislead folks
into thinking it represented an *alternative* to those other header
files?

rday
-- 
========================================================================
Robert P. J. Day
Linux Consulting, Training and Annoying Kernel Pedantry
Waterloo, Ontario, CANADA

http://fsdev.net/wiki/index.php?title=Main_Page
========================================================================

Re: why is it called "asm-generic/atomic.h"?

[Stefan Richter]

Robert P. J. Day wrote:
>   i'm just curious -- why does that particular header file have that
> name?  its opening comment reads:
> 
>  * Allows to provide arch independent atomic definitions without the need to
>  * edit all arch specific atomic.h files.
> 
> but that's *not* what that header file does.

The file name is correct, and the comment is correct too.  It indeed
_allows_ to define architecture-independent operations on atomic types,
and it currently does so for atomic_long_t.  There is no need to do so
for atomic_t, because all architectures already had their own set of
atomic_t operations when asm-generic/atomic.h was added.  (And I presume
they varied too much to justify an additional generic implementation
plus #ifndef HAVE_ARCH_SOMETHING games.)

PS:  The atomic_long_t operations currently don't need to be protected
by #ifndef HAVE_ARCH_SOMETHING and won't need to be in foreseeable
future, therefore they don't have this protection.
-- 
Stefan Richter
-=====-=-=== -==- --===
http://arcgraph.de/sr/