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path: root/drivers/oprofile/oprof.c
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Diffstat (limited to 'drivers/oprofile/oprof.c')
-rw-r--r--drivers/oprofile/oprof.c71
1 files changed, 70 insertions, 1 deletions
diff --git a/drivers/oprofile/oprof.c b/drivers/oprofile/oprof.c
index 3cffce90f82..dc8a0428260 100644
--- a/drivers/oprofile/oprof.c
+++ b/drivers/oprofile/oprof.c
@@ -12,6 +12,8 @@
#include <linux/init.h>
#include <linux/oprofile.h>
#include <linux/moduleparam.h>
+#include <linux/workqueue.h>
+#include <linux/time.h>
#include <asm/mutex.h>
#include "oprof.h"
@@ -87,6 +89,69 @@ out:
return err;
}
+#ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
+
+static void switch_worker(struct work_struct *work);
+static DECLARE_DELAYED_WORK(switch_work, switch_worker);
+
+static void start_switch_worker(void)
+{
+ if (oprofile_ops.switch_events)
+ schedule_delayed_work(&switch_work, oprofile_time_slice);
+}
+
+static void stop_switch_worker(void)
+{
+ cancel_delayed_work_sync(&switch_work);
+}
+
+static void switch_worker(struct work_struct *work)
+{
+ if (oprofile_ops.switch_events())
+ return;
+
+ atomic_inc(&oprofile_stats.multiplex_counter);
+ start_switch_worker();
+}
+
+/* User inputs in ms, converts to jiffies */
+int oprofile_set_timeout(unsigned long val_msec)
+{
+ int err = 0;
+ unsigned long time_slice;
+
+ mutex_lock(&start_mutex);
+
+ if (oprofile_started) {
+ err = -EBUSY;
+ goto out;
+ }
+
+ if (!oprofile_ops.switch_events) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ time_slice = msecs_to_jiffies(val_msec);
+ if (time_slice == MAX_JIFFY_OFFSET) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ oprofile_time_slice = time_slice;
+
+out:
+ mutex_unlock(&start_mutex);
+ return err;
+
+}
+
+#else
+
+static inline void start_switch_worker(void) { }
+static inline void stop_switch_worker(void) { }
+
+#endif
/* Actually start profiling (echo 1>/dev/oprofile/enable) */
int oprofile_start(void)
@@ -108,6 +173,8 @@ int oprofile_start(void)
if ((err = oprofile_ops.start()))
goto out;
+ start_switch_worker();
+
oprofile_started = 1;
out:
mutex_unlock(&start_mutex);
@@ -123,6 +190,9 @@ void oprofile_stop(void)
goto out;
oprofile_ops.stop();
oprofile_started = 0;
+
+ stop_switch_worker();
+
/* wake up the daemon to read what remains */
wake_up_buffer_waiter();
out:
@@ -155,7 +225,6 @@ post_sync:
mutex_unlock(&start_mutex);
}
-
int oprofile_set_backtrace(unsigned long val)
{
int err = 0;