[PATCH 22/30] sched: remove prio preference from balance decisions

[Peter Zijlstra]

Priority looses much of its meaning in a hierarchical context. So don't
use it in balance decisions.

Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
---
 kernel/sched.c |   12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

Index: linux-2.6/kernel/sched.c
===================================================================
--- linux-2.6.orig/kernel/sched.c
+++ linux-2.6/kernel/sched.c
@@ -2884,7 +2884,7 @@ balance_tasks(struct rq *this_rq, int th
 	      enum cpu_idle_type idle, int *all_pinned,
 	      int *this_best_prio, struct rq_iterator *iterator)
 {
-	int loops = 0, pulled = 0, pinned = 0, skip_for_load;
+	int loops = 0, pulled = 0, pinned = 0;
 	struct task_struct *p;
 	long rem_load_move = max_load_move;
 
@@ -2900,14 +2900,8 @@ balance_tasks(struct rq *this_rq, int th
 next:
 	if (!p || loops++ > sysctl_sched_nr_migrate)
 		goto out;
-	/*
-	 * To help distribute high priority tasks across CPUs we don't
-	 * skip a task if it will be the highest priority task (i.e. smallest
-	 * prio value) on its new queue regardless of its load weight
-	 */
-	skip_for_load = (p->se.load.weight >> 1) > rem_load_move +
-							 SCHED_LOAD_SCALE_FUZZ;
-	if ((skip_for_load && p->prio >= *this_best_prio) ||
+
+	if ((p->se.load.weight >> 1) > rem_load_move ||
 	    !can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) {
 		p = iterator->next(iterator->arg);
 		goto next;

-- 

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