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authorMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>2008-07-18 12:16:16 -0400
committerIngo Molnar <mingo@elte.hu>2008-10-14 10:29:05 +0200
commit4a0897526bbc5c6ac0df80b16b8c60339e717ae2 (patch)
treeaa8eb17c791cdff175f8cd6cb76f02d05f00029a /samples/tracepoints/tracepoint-probe-sample.c
parent24b8d831d56aac7907752d22d2aba5d8127db6f6 (diff)
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>
Diffstat (limited to 'samples/tracepoints/tracepoint-probe-sample.c')
-rw-r--r--samples/tracepoints/tracepoint-probe-sample.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/samples/tracepoints/tracepoint-probe-sample.c b/samples/tracepoints/tracepoint-probe-sample.c
new file mode 100644
index 00000000000..55abfdda4bd
--- /dev/null
+++ b/samples/tracepoints/tracepoint-probe-sample.c
@@ -0,0 +1,55 @@
+/*
+ * tracepoint-probe-sample.c
+ *
+ * sample tracepoint probes.
+ */
+
+#include <linux/module.h>
+#include <linux/file.h>
+#include <linux/dcache.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)
+{
+ path_get(&file->f_path);
+ dget(file->f_path.dentry);
+ printk(KERN_INFO "Event is encountered with filename %s\n",
+ file->f_path.dentry->d_name.name);
+ dput(file->f_path.dentry);
+ path_put(&file->f_path);
+}
+
+static void probe_subsys_eventb(void)
+{
+ printk(KERN_INFO "Event B is encountered\n");
+}
+
+int __init tp_sample_trace_init(void)
+{
+ int ret;
+
+ ret = register_trace_subsys_event(probe_subsys_event);
+ WARN_ON(ret);
+ ret = register_trace_subsys_eventb(probe_subsys_eventb);
+ WARN_ON(ret);
+
+ return 0;
+}
+
+module_init(tp_sample_trace_init);
+
+void __exit tp_sample_trace_exit(void)
+{
+ unregister_trace_subsys_eventb(probe_subsys_eventb);
+ 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");