ftrace: comment code

This is first installment of adding documentation to the ftrace.
Expect many more patches of this kind in the near future.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 7 insertions, 0 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index b0ca7473671b..21c29ee13e53 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -294,6 +294,13 @@ extern long ns2usecs(cycle_t nsec);
 
 extern unsigned long trace_flags;
 
+/*
+ * trace_iterator_flags is an enumeration that defines bit
+ * positions into trace_flags that controls the output.
+ *
+ * NOTE: These bits must match the trace_options array in
+ *       trace.c.
+ */
 enum trace_iterator_flags {
         TRACE_ITER_PRINT_PARENT         = 0x01,
         TRACE_ITER_SYM_OFFSET           = 0x02,