Re: [PATCH -next 1/2] mm/slab: add is_kmalloc_cache() helper macro

[Andrew Morton]

On Tue, 22 Nov 2022 13:30:19 +0800 Feng Tang <feng.tang@xxxxxxxxx> wrote:

> > If so, that's always best.  For (silly) example, consider the behaviour
> > of
> > 
> > 	x = is_kmalloc_cache(s++);
> > 
> > with and without CONFIG_SLOB.
> 
> Another solution I can think of is putting the implementation into
> slab_common.c, like the below?

I'm not sure that's much of an improvement on the macro :(

How about we go with the macro and avoid the
expression-with-side-effects gotcha (and the potential CONFIG_SLOB=n
unused-variable gotcha)?  That would involve evaluating the arg within
the CONFIG_SLOB=y version of the macro.