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

[Javi Merino]

On Mon, Mar 23, 2015 at 05:04:16PM +0000, Javi Merino wrote:
> 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.

Nah, thinking about it and seeing the other macros in this file
(esp. DIV_ROUND_UP() and DIV_ROUND_UP_ULL()) I don't think a static
function gives you anything.  I'll just modify the macro to look similar
to DIV_ROUND_CLOSEST()

Cheers,
Javi