From ec680cfed03abaacb044cf70e8fb0e857dd992a4 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Wed, 11 Jul 2012 20:26:32 +0200
Subject: [PATCH] --- yaml --- r: 323588 b: refs/heads/master c:
 1e1a689f10a27a4fe1ab9b4c6db04fa7232746a5 h: refs/heads/master v: v3

---
 [refs]                 | 2 +-
 trunk/kernel/rcutree.c | 5 ++++-
 trunk/kernel/rcutree.h | 1 +
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 85f1805dcf37..d71e983a8c32 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: c5d900bf676b1e2a61c44483932c8088651bbb4e
+refs/heads/master: 1e1a689f10a27a4fe1ab9b4c6db04fa7232746a5
diff --git a/trunk/kernel/rcutree.c b/trunk/kernel/rcutree.c
index d62c04482228..6b82a9565149 100644
--- a/trunk/kernel/rcutree.c
+++ b/trunk/kernel/rcutree.c
@@ -206,6 +206,9 @@ EXPORT_SYMBOL_GPL(rcu_note_context_switch);
 DEFINE_PER_CPU(struct rcu_dynticks, rcu_dynticks) = {
 	.dynticks_nesting = DYNTICK_TASK_EXIT_IDLE,
 	.dynticks = ATOMIC_INIT(1),
+#ifdef CONFIG_RCU_USER_QS
+	.ignore_user_qs = true,
+#endif
 };
 
 static int blimit = 10;		/* Maximum callbacks per rcu_do_batch. */
@@ -430,7 +433,7 @@ void rcu_user_enter(void)
 
 	local_irq_save(flags);
 	rdtp = &__get_cpu_var(rcu_dynticks);
-	if (!rdtp->in_user) {
+	if (!rdtp->ignore_user_qs && !rdtp->in_user) {
 		rdtp->in_user = true;
 		rcu_eqs_enter(1);
 	}
diff --git a/trunk/kernel/rcutree.h b/trunk/kernel/rcutree.h
index 10cc2f9f8433..5faf05d68326 100644
--- a/trunk/kernel/rcutree.h
+++ b/trunk/kernel/rcutree.h
@@ -103,6 +103,7 @@ struct rcu_dynticks {
 	int tick_nohz_enabled_snap; /* Previously seen value from sysfs. */
 #endif /* #ifdef CONFIG_RCU_FAST_NO_HZ */
 #ifdef CONFIG_RCU_USER_QS
+	bool ignore_user_qs;	    /* Treat userspace as extended QS or not */
 	bool in_user;		    /* Is the CPU in userland from RCU POV? */
 #endif
 };