Re: [PATCH 1/4] kernel.h: Implement DIV_ROUND_CLOSEST_ULL

[Javi Merino]

On Mon, Mar 23, 2015 at 12:34:04PM +0000, Jeff Epler wrote:
> On Fri, Mar 20, 2015 at 11:14:40AM +0000, Javi Merino wrote:
> > +/*
> > + * Same as above but for u64 dividends.  divisor must be a 32-bit
> > + * number.
> > + */
> > +#define DIV_ROUND_CLOSEST_ULL(x, divisor)(		\
> > +{							\
> > +	unsigned long long _tmp = (x) + (divisor) / 2;	\
> > +	do_div(_tmp, divisor);				\
> > +	_tmp;						\
> > +}							\
> > +)
> 
> The macro evaluates 'divisor' twice.

Good catch.  That needs to be fixed.  I could do the typeof trick that
DIV_ROUND_CLOSEST() does but it's probably better to just create a
static function as Alex Elder suggests.  I'll send a v2 tomorrow with
a static function instead.

Cheers,
Javi

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/