Merge branches 'tracing/branch-tracer', 'tracing/fastboot', 'tracing/ftrace', 'tracin...

[linux-2.6-omap-h63xx.git] / Documentation / markers.txt

diff --git a/Documentation/markers.txt b/Documentation/markers.txt
index 089f6138fcd94249a6444ca3a932a50c263098e1..6d275e4ef385d71acc6a931cc59fb5e9dfdf4eb0 100644 (file)
--- a/Documentation/markers.txt
+++ b/Documentation/markers.txt
@@ -70,6 +70,20 @@ a printk warning which identifies the inconsistency:
 
 "Format mismatch for probe probe_name (format), marker (format)"
 
+Another way to use markers is to simply define the marker without generating any
+function call to actually call into the marker. This is useful in combination
+with tracepoint probes in a scheme like this :
+
+void probe_tracepoint_name(unsigned int arg1, struct task_struct *tsk);
+
+DEFINE_MARKER_TP(marker_eventname, tracepoint_name, probe_tracepoint_name,
+       "arg1 %u pid %d");
+
+notrace void probe_tracepoint_name(unsigned int arg1, struct task_struct *tsk)
+{
+       struct marker *marker = &GET_MARKER(kernel_irq_entry);
+       /* write data to trace buffers ... */
+}
 
 * Probe / marker example