Messages in this thread | | | Date | Mon, 3 Sep 2007 21:55:20 +0200 (CEST) | From | Roman Zippel <> | Subject | Re: [ANNOUNCE/RFC] Really Simple Really Fair Scheduler |
| |
Hi,
On Mon, 3 Sep 2007, Ingo Molnar wrote:
> My next question then is about this code of yours in the wakeup path: > > +static void > +enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) > +{ > + kclock_t min_time; > + > + verify_queue(cfs_rq, cfs_rq->curr != se, se); > + min_time = get_time_avg(cfs_rq) - se->req_weight_inv; > + if ((kclock_t)(se->time_norm - min_time) < 0) > + se->time_norm = min_time; > > why do you only use the "min_time" if the pre-sleep time_norm is smaller > than the min_time? Here 'min_time' is close to the current average.
It's a variation of the sleeper bonus. Let's assume two running tasks which have been running for 95ms and 105ms and a time slice of 10ms, the average is thus 100ms. If the new task has been sleeping for a while it starts at 90ms, if the task had been running lately it doesn't get this bonus again.
> Shouldnt here the woken up task be set to the average time, like i did > it in the crude prototype: > > + se->exec_runtime = avg_exec_runtime(cfs_rq);
That would be equivalent to simply clearing wait_runtime in CFS.
bye, Roman - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |