From f18632b8d06dc3a65f949e6ee657eabb88e20ad7 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Thu, 9 Apr 2009 10:53:44 +0200
Subject: [PATCH] --- yaml --- r: 147358 b: refs/heads/master c:
 9ee318a7825929bc3734110b83ae8e20e53d9de3 h: refs/heads/master v: v3

---
 [refs]                      |  2 +-
 trunk/kernel/perf_counter.c | 39 ++++++++++++++++++++++++++++++++++---
 2 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/[refs] b/[refs]
index f8419936aace..d228936ab00b 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b3828ebb3901adfe989d8d4157ed28247aeec132
+refs/heads/master: 9ee318a7825929bc3734110b83ae8e20e53d9de3
diff --git a/trunk/kernel/perf_counter.c b/trunk/kernel/perf_counter.c
index b07195bbd228..76376ecb23b5 100644
--- a/trunk/kernel/perf_counter.c
+++ b/trunk/kernel/perf_counter.c
@@ -38,6 +38,10 @@ int perf_max_counters __read_mostly = 1;
 static int perf_reserved_percpu __read_mostly;
 static int perf_overcommit __read_mostly = 1;
 
+static atomic_t nr_mmap_tracking __read_mostly;
+static atomic_t nr_munmap_tracking __read_mostly;
+static atomic_t nr_comm_tracking __read_mostly;
+
 /*
  * Mutex for (sysadmin-configurable) counter reservations:
  */
@@ -1186,6 +1190,13 @@ static void free_counter(struct perf_counter *counter)
 {
 	perf_pending_sync(counter);
 
+	if (counter->hw_event.mmap)
+		atomic_dec(&nr_mmap_tracking);
+	if (counter->hw_event.munmap)
+		atomic_dec(&nr_munmap_tracking);
+	if (counter->hw_event.comm)
+		atomic_dec(&nr_comm_tracking);
+
 	if (counter->destroy)
 		counter->destroy(counter);
 
@@ -2005,7 +2016,12 @@ static void perf_counter_comm_event(struct perf_comm_event *comm_event)
 
 void perf_counter_comm(struct task_struct *task)
 {
-	struct perf_comm_event comm_event = {
+	struct perf_comm_event comm_event;
+
+	if (!atomic_read(&nr_comm_tracking))
+		return;
+       
+	comm_event = (struct perf_comm_event){
 		.task	= task,
 		.event  = {
 			.header = { .type = PERF_EVENT_COMM, },
@@ -2128,7 +2144,12 @@ static void perf_counter_mmap_event(struct perf_mmap_event *mmap_event)
 void perf_counter_mmap(unsigned long addr, unsigned long len,
 		       unsigned long pgoff, struct file *file)
 {
-	struct perf_mmap_event mmap_event = {
+	struct perf_mmap_event mmap_event;
+
+	if (!atomic_read(&nr_mmap_tracking))
+		return;
+
+	mmap_event = (struct perf_mmap_event){
 		.file   = file,
 		.event  = {
 			.header = { .type = PERF_EVENT_MMAP, },
@@ -2146,7 +2167,12 @@ void perf_counter_mmap(unsigned long addr, unsigned long len,
 void perf_counter_munmap(unsigned long addr, unsigned long len,
 			 unsigned long pgoff, struct file *file)
 {
-	struct perf_mmap_event mmap_event = {
+	struct perf_mmap_event mmap_event;
+
+	if (!atomic_read(&nr_munmap_tracking))
+		return;
+
+	mmap_event = (struct perf_mmap_event){
 		.file   = file,
 		.event  = {
 			.header = { .type = PERF_EVENT_MUNMAP, },
@@ -2725,6 +2751,13 @@ perf_counter_alloc(struct perf_counter_hw_event *hw_event,
 
 	counter->hw_ops = hw_ops;
 
+	if (counter->hw_event.mmap)
+		atomic_inc(&nr_mmap_tracking);
+	if (counter->hw_event.munmap)
+		atomic_inc(&nr_munmap_tracking);
+	if (counter->hw_event.comm)
+		atomic_inc(&nr_comm_tracking);
+
 	return counter;
 }