From eff6dabd32c4a2608e9c70bdeb89386ac7a90780 Mon Sep 17 00:00:00 2001
From: "Paul E. McKenney" <paul.mckenney@linaro.org>
Date: Tue, 21 Jun 2011 22:43:26 -0700
Subject: [PATCH] --- yaml --- r: 268959 b: refs/heads/master c:
 385680a9487d2f85382ad6d74e2a15837e47bfd9 h: refs/heads/master i:   268957:
 be0d77882638093323c74844ecc80c4948ef89b8   268955:
 cdb3a6e5a0b26de35c28d0042ac2379bcd90292c   268951:
 9cc0cd828bc973d0835d2b187571270b2b60fc53   268943:
 16907c233c034e012969696ceb93f01272308651   268927:
 eeb58de806585f6ec14b6be91675cdc2483628fe v: v3

---
 [refs]                           |  2 +-
 trunk/include/trace/events/rcu.h |  3 +++
 trunk/kernel/rcutree_plugin.h    | 12 ++++++++++++
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index aaea50a3be7a..0a7d4e14bca7 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: eab0993c7ba5c7d9b3613d6037e0f31f0ccbe181
+refs/heads/master: 385680a9487d2f85382ad6d74e2a15837e47bfd9
diff --git a/trunk/include/trace/events/rcu.h b/trunk/include/trace/events/rcu.h
index 508824e5a77d..ac52aba00a3e 100644
--- a/trunk/include/trace/events/rcu.h
+++ b/trunk/include/trace/events/rcu.h
@@ -13,6 +13,9 @@
  * "Start <activity>" -- Mark the start of the specified activity,
  *			 such as "context switch".  Nesting is permitted.
  * "End <activity>" -- Mark the end of the specified activity.
+ *
+ * An "@" character within "<activity>" is a comment character: Data
+ * reduction scripts will ignore the "@" and the remainder of the line.
  */
 TRACE_EVENT(rcu_utilization,
 
diff --git a/trunk/kernel/rcutree_plugin.h b/trunk/kernel/rcutree_plugin.h
index ecd48a2e3eeb..94d9ca1e4061 100644
--- a/trunk/kernel/rcutree_plugin.h
+++ b/trunk/kernel/rcutree_plugin.h
@@ -1219,9 +1219,12 @@ static int rcu_boost_kthread(void *arg)
 	int spincnt = 0;
 	int more2boost;
 
+	trace_rcu_utilization("Start boost kthread@init");
 	for (;;) {
 		rnp->boost_kthread_status = RCU_KTHREAD_WAITING;
+		trace_rcu_utilization("End boost kthread@rcu_wait");
 		rcu_wait(rnp->boost_tasks || rnp->exp_tasks);
+		trace_rcu_utilization("Start boost kthread@rcu_wait");
 		rnp->boost_kthread_status = RCU_KTHREAD_RUNNING;
 		more2boost = rcu_boost(rnp);
 		if (more2boost)
@@ -1229,11 +1232,14 @@ static int rcu_boost_kthread(void *arg)
 		else
 			spincnt = 0;
 		if (spincnt > 10) {
+			trace_rcu_utilization("End boost kthread@rcu_yield");
 			rcu_yield(rcu_boost_kthread_timer, (unsigned long)rnp);
+			trace_rcu_utilization("Start boost kthread@rcu_yield");
 			spincnt = 0;
 		}
 	}
 	/* NOTREACHED */
+	trace_rcu_utilization("End boost kthread@notreached");
 	return 0;
 }
 
@@ -1490,9 +1496,12 @@ static int rcu_cpu_kthread(void *arg)
 	char work;
 	char *workp = &per_cpu(rcu_cpu_has_work, cpu);
 
+	trace_rcu_utilization("Start CPU kthread@init");
 	for (;;) {
 		*statusp = RCU_KTHREAD_WAITING;
+		trace_rcu_utilization("End CPU kthread@rcu_wait");
 		rcu_wait(*workp != 0 || kthread_should_stop());
+		trace_rcu_utilization("Start CPU kthread@rcu_wait");
 		local_bh_disable();
 		if (rcu_cpu_kthread_should_stop(cpu)) {
 			local_bh_enable();
@@ -1513,11 +1522,14 @@ static int rcu_cpu_kthread(void *arg)
 			spincnt = 0;
 		if (spincnt > 10) {
 			*statusp = RCU_KTHREAD_YIELDING;
+			trace_rcu_utilization("End CPU kthread@rcu_yield");
 			rcu_yield(rcu_cpu_kthread_timer, (unsigned long)cpu);
+			trace_rcu_utilization("Start CPU kthread@rcu_yield");
 			spincnt = 0;
 		}
 	}
 	*statusp = RCU_KTHREAD_STOPPED;
+	trace_rcu_utilization("End CPU kthread@term");
 	return 0;
 }