From c3a2ae3d93c0f10d29c071f599764d00b8de00cb Mon Sep 17 00:00:00 2001
From: Steven Rostedt <srostedt@redhat.com>
Date: Wed, 29 Jul 2009 00:21:23 -0400
Subject: [PATCH] sched: Add new prio to cpupri before removing old prio

We need to add the new prio to the cpupri accounting before
removing the old prio. This is because removing the old prio
first will open a race window where the cpu will be removed
from pri_active. In this case the cpu will not be visible for
RT push and pulls. This could cause a RT task to not migrate
appropriately, and create a very large latency.

This bug was found with the use of ftrace sched events and
trace_printk.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090729042526.438281019@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
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