Attachment 217181 Details for Bug 319911 – Mikes's patch to avoid expired starvation

[patch] Mikes's patch to avoid expired starvation

avoid-interactive-starvation.patch (text/plain), 2.04 KB, created by Bryn M. Reeves on 2007-10-05 09:39:51 UTC

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Creator: Bryn M. Reeves

Created: 2007-10-05 09:39:51 UTC

Size: 2.04 KB

patch

obsolete

>--- kernel/sched.c.org	2006-03-17 14:48:35.000000000 +0100
>+++ kernel/sched.c	2006-03-17 17:41:25.000000000 +0100
>@@ -662,11 +662,30 @@
> }
> 
> /*
>+ * We place interactive tasks back into the active array, if possible.
>+ *
>+ * To guarantee that this does not starve expired tasks we ignore the
>+ * interactivity of a task if the first expired task had to wait more
>+ * than a 'reasonable' amount of time. This deadline timeout is
>+ * load-dependent, as the frequency of array switched decreases with
>+ * increasing number of running tasks. We also ignore the interactivity
>+ * if a better static_prio task has expired:
>+ */
>+#define EXPIRED_STARVING(rq) \
>+	((STARVATION_LIMIT && ((rq)->expired_timestamp && \
>+		(jiffies - (rq)->expired_timestamp >= \
>+			STARVATION_LIMIT * ((rq)->nr_running) + 1))) || \
>+			((rq)->curr->static_prio > (rq)->best_expired_prio))
>+
>+/*
>  * __activate_task - move a task to the runqueue.
>  */
> static inline void __activate_task(task_t *p, runqueue_t *rq)
> {
>-	enqueue_task(p, rq->active);
>+	prio_array_t *array = rq->active;
>+	if (unlikely(EXPIRED_STARVING(rq)))
>+		array = rq->expired;
>+	enqueue_task(p, array);
> 	rq->nr_running++;
> }
> 
>@@ -2461,22 +2480,6 @@
> }
> 
> /*
>- * We place interactive tasks back into the active array, if possible.
>- *
>- * To guarantee that this does not starve expired tasks we ignore the
>- * interactivity of a task if the first expired task had to wait more
>- * than a 'reasonable' amount of time. This deadline timeout is
>- * load-dependent, as the frequency of array switched decreases with
>- * increasing number of running tasks. We also ignore the interactivity
>- * if a better static_prio task has expired:
>- */
>-#define EXPIRED_STARVING(rq) \
>-	((STARVATION_LIMIT && ((rq)->expired_timestamp && \
>-		(jiffies - (rq)->expired_timestamp >= \
>-			STARVATION_LIMIT * ((rq)->nr_running) + 1))) || \
>-			((rq)->curr->static_prio > (rq)->best_expired_prio))
>-
>-/*
>  * Account user cpu time to a process.
>  * @p: the process that the cpu time gets accounted to
>  * @hardirq_offset: the offset to subtract from hardirq_count()
>

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Attachments on bug 319911: 217181 | 217221 | 217891