tracing: tracepoints, samples

[linux-2.6-omap-h63xx.git] / samples / tracepoints / tracepoint-probe-sample2.c

diff --git a/samples/tracepoints/tracepoint-probe-sample2.c b/samples/tracepoints/tracepoint-probe-sample2.c
new file mode 100644 (file)
index 0000000..5e9fcf4
--- /dev/null
+++ b/samples/tracepoints/tracepoint-probe-sample2.c
@@ -0,0 +1,42 @@
+/*
+ * tracepoint-probe-sample2.c
+ *
+ * 2nd sample tracepoint probes.
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include "tp-samples-trace.h"
+
+/*
+ * Here the caller only guarantees locking for struct file and struct inode.
+ * Locking must therefore be done in the probe to use the dentry.
+ */
+static void probe_subsys_event(struct inode *inode, struct file *file)
+{
+       printk(KERN_INFO "Event is encountered with inode number %lu\n",
+               inode->i_ino);
+}
+
+int __init tp_sample_trace_init(void)
+{
+       int ret;
+
+       ret = register_trace_subsys_event(probe_subsys_event);
+       WARN_ON(ret);
+
+       return 0;
+}
+
+module_init(tp_sample_trace_init);
+
+void __exit tp_sample_trace_exit(void)
+{
+       unregister_trace_subsys_event(probe_subsys_event);
+}
+
+module_exit(tp_sample_trace_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Mathieu Desnoyers");
+MODULE_DESCRIPTION("Tracepoint Probes Samples");