Merge branch 'gp.2013.09.25a' into HEAD

gp.2013.09.25a: Topic branch for grace-period updates.

1 files changed, 31 insertions, 4 deletions

diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 1855d66bf705..cd95efa1da48 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -2113,15 +2113,22 @@ static void __call_rcu_nocb_enqueue(struct rcu_data *rdp,
 
 	/* If we are not being polled and there is a kthread, awaken it ... */
 	t = ACCESS_ONCE(rdp->nocb_kthread);
-	if (rcu_nocb_poll || !t)
+	if (rcu_nocb_poll || !t) {
+		trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
+				    TPS("WakeNotPoll"));
 		return;
+	}
 	len = atomic_long_read(&rdp->nocb_q_count);
 	if (old_rhpp == &rdp->nocb_head) {
 		wake_up(&rdp->nocb_wq); /* ... only if queue was empty ... */
 		rdp->qlen_last_fqs_check = 0;
+		trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu, TPS("WakeEmpty"));
 	} else if (len > rdp->qlen_last_fqs_check + qhimark) {
 		wake_up_process(t); /* ... or if many callbacks queued. */
 		rdp->qlen_last_fqs_check = LONG_MAX / 2;
+		trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu, TPS("WakeOvf"));
+	} else {
+		trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu, TPS("WakeNot"));
 	}
 	return;
 }
@@ -2145,10 +2152,12 @@ static bool __call_rcu_nocb(struct rcu_data *rdp, struct rcu_head *rhp,
 	if (__is_kfree_rcu_offset((unsigned long)rhp->func))
 		trace_rcu_kfree_callback(rdp->rsp->name, rhp,
 					 (unsigned long)rhp->func,
-					 rdp->qlen_lazy, rdp->qlen);
+					 -atomic_long_read(&rdp->nocb_q_count_lazy),
+					 -atomic_long_read(&rdp->nocb_q_count));
 	else
 		trace_rcu_callback(rdp->rsp->name, rhp,
-				   rdp->qlen_lazy, rdp->qlen);
+				   -atomic_long_read(&rdp->nocb_q_count_lazy),
+				   -atomic_long_read(&rdp->nocb_q_count));
 	return 1;
 }
 
@@ -2226,6 +2235,7 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp)
 static int rcu_nocb_kthread(void *arg)
 {
 	int c, cl;
+	bool firsttime = 1;
 	struct rcu_head *list;
 	struct rcu_head *next;
 	struct rcu_head **tail;
@@ -2234,14 +2244,27 @@ static int rcu_nocb_kthread(void *arg)
 	/* Each pass through this loop invokes one batch of callbacks */
 	for (;;) {
 		/* If not polling, wait for next batch of callbacks. */
-		if (!rcu_nocb_poll)
+		if (!rcu_nocb_poll) {
+			trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
+					    TPS("Sleep"));
 			wait_event_interruptible(rdp->nocb_wq, rdp->nocb_head);
+		} else if (firsttime) {
+			firsttime = 0;
+			trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
+					    TPS("Poll"));
+		}
 		list = ACCESS_ONCE(rdp->nocb_head);
 		if (!list) {
+			if (!rcu_nocb_poll)
+				trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
+						    TPS("WokeEmpty"));
 			schedule_timeout_interruptible(1);
 			flush_signals(current);
 			continue;
 		}
+		firsttime = 1;
+		trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
+				    TPS("WokeNonEmpty"));
 
 		/*
 		 * Extract queued callbacks, update counts, and wait
@@ -2262,7 +2285,11 @@ static int rcu_nocb_kthread(void *arg)
 			next = list->next;
 			/* Wait for enqueuing to complete, if needed. */
 			while (next == NULL && &list->next != tail) {
+				trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
+						    TPS("WaitQueue"));
 				schedule_timeout_interruptible(1);
+				trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
+						    TPS("WokeQueue"));
 				next = list->next;
 			}
 			debug_rcu_head_unqueue(list);