Re: PROBLEM: high load average when idle

Arjan van de Ven
2007-10-02T22:40:25Z

Linus Torvalds wrote:
>
> I wonder if the whole "round_jiffies()" thing should be written so that it
> never rounds down, or at least never rounds down to before the current
> second!

that's what it is supposed to do already...

166
167 if (j <= jiffies) /* rounding ate our timeout entirely; */
168 return original;
169 return j;
170 }

so there is always a gap of at least 1 jiffie no matter what

>
> I have to say, I also think it's a bit iffy to do "round_jiffies()" at all
> in that per-CPU kind of way. The "per-cpu" thing is quite possibly going
> to change by the time we actually add the timer, so the goal of trying to
> get wakeups to happen in "bunches" per CPU should really be done by
> setting a flag on the timer itself - so that we could do that rounding
> when the timer is actually added to the per-cpu queues!

it's pretty much the same thing though