sched-dont-add-rcu_preempt_depth-to-preempt_count-on.patch

From 9b96462de6efcdbbc7fb0c14c41444093de1c8ff Mon Sep 17 00:00:00 2001
From: Paul Gortmaker <paul.gortmaker@windriver.com>
Date: Sat, 22 Jan 2011 17:13:14 -0500
Subject: [PATCH] sched: dont add rcu_preempt_depth to preempt_count on RT

This is one of several extractions from the merge up to 33-rc8.

See it in a git tip repo with:

   git diff 5f854cfc024622e4aae14d7cf422f6ff86278688^2 \
	5f854cfc024622e4aae14d7cf422f6ff86278688 kernel/sched.c

You can find the origin of this change in the tip merge commit:

     commit 5f854cfc024622e4aae14d7cf422f6ff86278688
     Merge: cc24da0 4ec62b2
     Author: Thomas Gleixner <tglx@linutronix.de>
     Date:   Sun Feb 21 20:17:22 2010 +0100

         Forward to 2.6.33-rc8

         Merge branch 'linus' into rt/head with a pile of conflicts.

         Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Normally there are not significant changes/additions in a merge commit that
are not from any other "normal" commit.  But in this case there are, so
break them out into separate explicit commits.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/kernel/sched.c b/kernel/sched.c
index 50e6608..a4c9f95 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -10083,7 +10083,11 @@ void __init sched_init(void)
 #if defined(CONFIG_DEBUG_SPINLOCK_SLEEP) || defined(CONFIG_DEBUG_PREEMPT)
 static inline int preempt_count_equals(int preempt_offset)
 {
-	int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth();
+	int nested = (preempt_count() & ~PREEMPT_ACTIVE);
+
+#ifndef CONFIG_PREEMPT_RT
+	nested += rcu_preempt_depth();
+#endif
 
 	return (nested == PREEMPT_INATOMIC_BASE + preempt_offset);
 }
-- 
1.7.1.1