tracing: tracepoints, samples

Tracepoint example code under samples/.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: 'Peter Zijlstra' <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 53 insertions, 0 deletions

diff --git a/samples/tracepoints/tracepoint-sample.c b/samples/tracepoints/tracepoint-sample.c
new file mode 100644
index 000000000000..4ae4b7fcc043
--- /dev/null
+++ b/samples/tracepoints/tracepoint-sample.c
@@ -0,0 +1,53 @@
+/* tracepoint-sample.c
+ *
+ * Executes a tracepoint when /proc/tracepoint-example is opened.
+ *
+ * (C) Copyright 2007 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
+ *
+ * This file is released under the GPLv2.
+ * See the file COPYING for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/proc_fs.h>
+#include "tp-samples-trace.h"
+
+struct proc_dir_entry *pentry_example;
+
+static int my_open(struct inode *inode, struct file *file)
+{
+        int i;
+
+        trace_subsys_event(inode, file);
+        for (i = 0; i < 10; i++)
+                trace_subsys_eventb();
+        return -EPERM;
+}
+
+static struct file_operations mark_ops = {
+        .open = my_open,
+};
+
+static int example_init(void)
+{
+        printk(KERN_ALERT "example init\n");
+        pentry_example = proc_create("tracepoint-example", 0444, NULL,
+                &mark_ops);
+        if (!pentry_example)
+                return -EPERM;
+        return 0;
+}
+
+static void example_exit(void)
+{
+        printk(KERN_ALERT "example exit\n");
+        remove_proc_entry("tracepoint-example", NULL);
+}
+
+module_init(example_init)
+module_exit(example_exit)
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Mathieu Desnoyers");
+MODULE_DESCRIPTION("Tracepoint example");