Re: [patch][rfc] quell interactive feeding frenzy

From: Con Kolivas
Date: Thu Apr 13 2006 - 06:17:20 EST


On Thursday 13 April 2006 17:41, Mike Galbraith wrote:
> This way also allowed me to eliminate the interactive agony of an array
> switch when at 100% cpu. Seems to work well. No more agony, only tiny
> pin pricks.
>
> Anyway, interested readers will find a copy of irman2.c, which is nice
> for testing interactive starvation, attached. The effect is most
> noticeable with something like bonnie, which otherwise has zero chance
> against irman2. Just about anything will do though. Trying to fire up
> Amarok is good for a chuckle. Whatever. (if anyone plays with irman2
> on 2.6.16 or below, call it with -S 1)

Comments.

> +repeat:
> + while ((idx = find_next_bit(bitmap, MAX_PRIO, idx)) < MAX_PRIO) {

...

> + goto repeat;

...

> + if (rq->nr_running > 1)
> + requeue_starving(rq, now);

An O(n) function in scheduler_tick is probably not the way to tackle this.

--
-ck
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