Commit 01c8c57d authored Oct 24, 2008 by Peter Zijlstra Committed by Ingo Molnar Oct 24, 2008

sched: fix a find_busiest_group buglet



In one of the group load balancer patches:

	commit 408ed066
	Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
	Date:   Fri Jun 27 13:41:28 2008 +0200
	Subject: sched: hierarchical load vs find_busiest_group

The following change:

-               if (max_load - this_load + SCHED_LOAD_SCALE_FUZZ >=
+               if (max_load - this_load + 2*busiest_load_per_task >=
                                        busiest_load_per_task * imbn) {

made the condition always true, because imbn is [1,2].
Therefore, remove the 2*, and give the it a fair chance.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent 8c82a17e

kernel/sched.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -3344,7 +3344,7 @@ small_imbalance:
		} else
		this_load_per_task = cpu_avg_load_per_task(this_cpu);

		if (max_load - this_load + 2*busiest_load_per_task >=
		if (max_load - this_load + busiest_load_per_task >=
		busiest_load_per_task * imbn) {
		*imbalance = busiest_load_per_task;
		return busiest;

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