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

From: Robert P. J. Day
Date: Sun May 03 2009 - 08:23:27 EST


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

> On Sun, 3 May 2009, Pekka J Enberg wrote:
>
> > From: Pekka Enberg <penberg@xxxxxxxxxxxxxx>
> >
> > 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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