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sched: fix a find_busiest_group buglet

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In one of the group load balancer patches:

	commit 408ed066b11cf9ee4536573b4269ee3613bd735e
	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>
This commit is contained in:
Peter Zijlstra 2008-10-24 11:06:12 +02:00 committed by Ingo Molnar
parent 8c82a17e9c
commit 01c8c57d66
1 changed files with 1 additions and 1 deletions
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2
kernel/sched.c
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@ -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;