aboutsummaryrefslogtreecommitdiff
path: root/drivers/oprofile/oprof.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/oprofile/oprof.c')
-rw-r--r--drivers/oprofile/oprof.c188
1 files changed, 188 insertions, 0 deletions
diff --git a/drivers/oprofile/oprof.c b/drivers/oprofile/oprof.c
new file mode 100644
index 00000000000..b3f1cd6a24c
--- /dev/null
+++ b/drivers/oprofile/oprof.c
@@ -0,0 +1,188 @@
+/**
+ * @file oprof.c
+ *
+ * @remark Copyright 2002 OProfile authors
+ * @remark Read the file COPYING
+ *
+ * @author John Levon <levon@movementarian.org>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/oprofile.h>
+#include <linux/moduleparam.h>
+#include <asm/semaphore.h>
+
+#include "oprof.h"
+#include "event_buffer.h"
+#include "cpu_buffer.h"
+#include "buffer_sync.h"
+#include "oprofile_stats.h"
+
+struct oprofile_operations oprofile_ops;
+
+unsigned long oprofile_started;
+unsigned long backtrace_depth;
+static unsigned long is_setup;
+static DECLARE_MUTEX(start_sem);
+
+/* timer
+ 0 - use performance monitoring hardware if available
+ 1 - use the timer int mechanism regardless
+ */
+static int timer = 0;
+
+int oprofile_setup(void)
+{
+ int err;
+
+ down(&start_sem);
+
+ if ((err = alloc_cpu_buffers()))
+ goto out;
+
+ if ((err = alloc_event_buffer()))
+ goto out1;
+
+ if (oprofile_ops.setup && (err = oprofile_ops.setup()))
+ goto out2;
+
+ /* Note even though this starts part of the
+ * profiling overhead, it's necessary to prevent
+ * us missing task deaths and eventually oopsing
+ * when trying to process the event buffer.
+ */
+ if ((err = sync_start()))
+ goto out3;
+
+ is_setup = 1;
+ up(&start_sem);
+ return 0;
+
+out3:
+ if (oprofile_ops.shutdown)
+ oprofile_ops.shutdown();
+out2:
+ free_event_buffer();
+out1:
+ free_cpu_buffers();
+out:
+ up(&start_sem);
+ return err;
+}
+
+
+/* Actually start profiling (echo 1>/dev/oprofile/enable) */
+int oprofile_start(void)
+{
+ int err = -EINVAL;
+
+ down(&start_sem);
+
+ if (!is_setup)
+ goto out;
+
+ err = 0;
+
+ if (oprofile_started)
+ goto out;
+
+ oprofile_reset_stats();
+
+ if ((err = oprofile_ops.start()))
+ goto out;
+
+ oprofile_started = 1;
+out:
+ up(&start_sem);
+ return err;
+}
+
+
+/* echo 0>/dev/oprofile/enable */
+void oprofile_stop(void)
+{
+ down(&start_sem);
+ if (!oprofile_started)
+ goto out;
+ oprofile_ops.stop();
+ oprofile_started = 0;
+ /* wake up the daemon to read what remains */
+ wake_up_buffer_waiter();
+out:
+ up(&start_sem);
+}
+
+
+void oprofile_shutdown(void)
+{
+ down(&start_sem);
+ sync_stop();
+ if (oprofile_ops.shutdown)
+ oprofile_ops.shutdown();
+ is_setup = 0;
+ free_event_buffer();
+ free_cpu_buffers();
+ up(&start_sem);
+}
+
+
+int oprofile_set_backtrace(unsigned long val)
+{
+ int err = 0;
+
+ down(&start_sem);
+
+ if (oprofile_started) {
+ err = -EBUSY;
+ goto out;
+ }
+
+ if (!oprofile_ops.backtrace) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ backtrace_depth = val;
+
+out:
+ up(&start_sem);
+ return err;
+}
+
+static int __init oprofile_init(void)
+{
+ int err;
+
+ err = oprofile_arch_init(&oprofile_ops);
+
+ if (err < 0 || timer) {
+ printk(KERN_INFO "oprofile: using timer interrupt.\n");
+ oprofile_timer_init(&oprofile_ops);
+ }
+
+ err = oprofilefs_register();
+ if (err)
+ oprofile_arch_exit();
+
+ return err;
+}
+
+
+static void __exit oprofile_exit(void)
+{
+ oprofilefs_unregister();
+ oprofile_arch_exit();
+}
+
+
+module_init(oprofile_init);
+module_exit(oprofile_exit);
+
+module_param_named(timer, timer, int, 0644);
+MODULE_PARM_DESC(timer, "force use of timer interrupt");
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("John Levon <levon@movementarian.org>");
+MODULE_DESCRIPTION("OProfile system profiler");