Re: [RFC] exponential update_wall_time

From: john stultz
Date: Wed Sep 27 2006 - 19:20:43 EST

On Wed, 2006-09-27 at 15:05 -0700, Andrew Morton wrote:
> On Wed, 27 Sep 2006 12:35:33 -0700
> john stultz <johnstul@xxxxxxxxxx> wrote:
> > + while (offset > clock->cycle_interval << (shift + 1))
> > + shift++;
> hurts my brain.

Yea. Its not the most obvious patch, but the complexity is pretty

> I have a vague feeling that this can be done with
> something like ffz(~(offset/clock->cycle_interval))+epsilon, but that hurts
> my brain too.

Agreed. I don't want to obfuscate this code much more. In my opinion,
the loop is tightly bounded and not expensive enough to try to optimize.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at