Re: [PATCH 2/2 v4] sched: Rewrite per entity runnable load average tracking

From: Yuyang Du
Date: Tue Jul 29 2014 - 04:59:19 EST


On Mon, Jul 28, 2014 at 12:48:37PM +0200, Peter Zijlstra wrote:
> > +static __always_inline u64 decay_load(u64 val, u64 n)
> > +{
> > + if (likely(val <= UINT_MAX))
> > + val = decay_load32(val, n);
> > + else {
> > + val *= (u32)decay_load32(1 << 15, n);
> > + val >>= 15;
> > + }
> > +
> > + return val;
> > +}
>
> Please just use mul_u64_u32_shr().
>
> /me continues reading the rest of it..

Good. Since 128bit is considered in mul_u64_u32_shr, load_sum can
afford more tasks :)
--
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/