Re: [PATCH] SLQB: Use _RET_IP_ instead of __builtin_return_address(0)

["Robert P. J. Day" <rpjday@crashcourse.ca>]

On Sun, 3 May 2009, Robert P. J. Day wrote:

> On Sun, 3 May 2009, Pekka J Enberg wrote:
>
> > From: Pekka Enberg <penberg@cs.helsinki.fi>
> >
> > This patch changes SLQB to use the shorter _RET_IP_ form for consistency
> > with SLUB and to prepare SQLB for eventual kmemtrace hooks.
>
> ... big snip ...
>
> >  void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags)
> >  {
> > -	return __kmem_cache_alloc(s, gfpflags, __builtin_return_address(0));
> > +	return __kmem_cache_alloc(s, gfpflags, _RET_IP_);
> >  }
>
>   since i originally pointed out this possible simplification, i might
> as well also point out that the above is not necessarily correct.  in
> include/linux/kernel.h:
>
> #define _RET_IP_   (unsigned long)__builtin_return_address(0)
>
> as in, _RET_IP_ represents the **(unsigned long)** cast of that
> (void*) value.  so, technically, that's not merely an aesthetic
> replacement.  is that still what you wanted?

  whoops, never mind, i didn't read far enough to notice you were
making that change throughout the code.  carry on.

rday
--

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Robert P. J. Day                               Waterloo, Ontario, CANADA

        Linux Consulting, Training and Annoying Kernel Pedantry.

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