[PATCH] sched: smpnice - fix average load per run queue calculations

[PATCH] sched: smpnice - fix average load per run queue calculations

[Peter Williams]

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The logical value to use for the average load per task on a run queue 
without any runnable tasks is the "default" load for a nice==0 task. 
Failure to do this may lead to anomalies in try_to_wake_up(), etc.

Signed-off-by: Peter Williams <pwil3058@bigpond.com.au>

Peter
-- 
Peter Williams                                   pwil3058@bigpond.net.au

"Learning, n. The kind of ignorance distinguishing the studious."
  -- Ambrose Bierce

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Index: MM-2.6.X/kernel/sched.c
===================================================================
--- MM-2.6.X.orig/kernel/sched.c	2006-02-27 17:18:12.000000000 +1100
+++ MM-2.6.X/kernel/sched.c	2006-02-27 17:19:52.000000000 +1100
@@ -1058,7 +1058,7 @@ static inline unsigned long cpu_avg_load
 	runqueue_t *rq = cpu_rq(cpu);
 	unsigned long n = rq->nr_running;
 
-	return n ?  rq->raw_weighted_load / n : rq->raw_weighted_load;
+	return n ?  rq->raw_weighted_load / n : SCHED_LOAD_SCALE;
 }
 
 /*

Re: [PATCH] sched: smpnice - fix average load per run queue calculations

[Peter Williams]

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Peter Williams wrote:
> The logical value to use for the average load per task on a run queue 
> without any runnable tasks is the "default" load for a nice==0 task. 
> Failure to do this may lead to anomalies in try_to_wake_up(), etc.
> 
> Signed-off-by: Peter Williams <pwil3058@bigpond.com.au>

I missed a bit.  Here's a fixed patch.

Signed-off-by: Peter Williams <pwil3058@bigpond.com.au>

Sorry,
Peter
-- 
Peter Williams                                   pwil3058@bigpond.net.au

"Learning, n. The kind of ignorance distinguishing the studious."
  -- Ambrose Bierce

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Index: MM-2.6.X/kernel/sched.c
===================================================================
--- MM-2.6.X.orig/kernel/sched.c	2006-02-27 17:18:12.000000000 +1100
+++ MM-2.6.X/kernel/sched.c	2006-02-27 17:53:49.000000000 +1100
@@ -1058,7 +1058,7 @@ static inline unsigned long cpu_avg_load
 	runqueue_t *rq = cpu_rq(cpu);
 	unsigned long n = rq->nr_running;
 
-	return n ?  rq->raw_weighted_load / n : rq->raw_weighted_load;
+	return n ?  rq->raw_weighted_load / n : SCHED_LOAD_SCALE;
 }
 
 /*
@@ -2153,6 +2153,8 @@ find_busiest_group(struct sched_domain *
 			min(busiest_load_per_task, max_load);
 		if (this_nr_running)
 			this_load_per_task /= this_nr_running;
+		else
+			this_load_per_task = SCHED_LOAD_SCALE;
 		pwr_now += this->cpu_power *
 			min(this_load_per_task, this_load);
 		pwr_now /= SCHED_LOAD_SCALE;