From fcd2383fe8ec7b514a9cc592afc1052abbc56f88 Mon Sep 17 00:00:00 2001
From: "Paul E. McKenney" <paul.mckenney@linaro.org>
Date: Thu, 13 Oct 2011 19:05:12 -0700
Subject: [PATCH] --- yaml --- r: 277213 b: refs/heads/master c:
 a7b152d5342c06e81ab0cf7d18345f69fa7e56b5 h: refs/heads/master i:   277211:
 b4144bf65f46c0e66ca9515be5acd5851969d4f5 v: v3

---
 [refs]                                      |  2 +-
 trunk/arch/powerpc/kernel/idle.c            | 16 ++++++++++++++--
 trunk/arch/powerpc/platforms/pseries/lpar.c |  4 ++++
 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/[refs] b/[refs]
index 4eba1ae22d8f..cdcf651acf41 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 416eb33cd60ef405e2860a186364e57bcb2d89f6
+refs/heads/master: a7b152d5342c06e81ab0cf7d18345f69fa7e56b5
diff --git a/trunk/arch/powerpc/kernel/idle.c b/trunk/arch/powerpc/kernel/idle.c
index 2e782a36d8f2..3cd73d1fc427 100644
--- a/trunk/arch/powerpc/kernel/idle.c
+++ b/trunk/arch/powerpc/kernel/idle.c
@@ -46,6 +46,12 @@ static int __init powersave_off(char *arg)
 }
 __setup("powersave=off", powersave_off);
 
+#if defined(CONFIG_PPC_PSERIES) && defined(CONFIG_TRACEPOINTS)
+static const bool idle_uses_rcu = 1;
+#else
+static const bool idle_uses_rcu;
+#endif
+
 /*
  * The body of the idle task.
  */
@@ -56,7 +62,10 @@ void cpu_idle(void)
 
 	set_thread_flag(TIF_POLLING_NRFLAG);
 	while (1) {
-		tick_nohz_idle_enter_norcu();
+		if (idle_uses_rcu)
+			tick_nohz_idle_enter();
+		else
+			tick_nohz_idle_enter_norcu();
 		while (!need_resched() && !cpu_should_die()) {
 			ppc64_runlatch_off();
 
@@ -93,7 +102,10 @@ void cpu_idle(void)
 
 		HMT_medium();
 		ppc64_runlatch_on();
-		tick_nohz_idle_exit_norcu();
+		if (idle_uses_rcu)
+			tick_nohz_idle_exit();
+		else
+			tick_nohz_idle_exit_norcu();
 		preempt_enable_no_resched();
 		if (cpu_should_die())
 			cpu_die();
diff --git a/trunk/arch/powerpc/platforms/pseries/lpar.c b/trunk/arch/powerpc/platforms/pseries/lpar.c
index 27a49508b410..52d429be6c76 100644
--- a/trunk/arch/powerpc/platforms/pseries/lpar.c
+++ b/trunk/arch/powerpc/platforms/pseries/lpar.c
@@ -555,6 +555,8 @@ void __trace_hcall_entry(unsigned long opcode, unsigned long *args)
 
 	(*depth)++;
 	trace_hcall_entry(opcode, args);
+	if (opcode == H_CEDE)
+		rcu_idle_enter();
 	(*depth)--;
 
 out:
@@ -575,6 +577,8 @@ void __trace_hcall_exit(long opcode, unsigned long retval,
 		goto out;
 
 	(*depth)++;
+	if (opcode == H_CEDE)
+		rcu_idle_exit();
 	trace_hcall_exit(opcode, retval, retbuf);
 	(*depth)--;