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Diffstat (limited to 'Documentation/trace/ftrace.rst')
| -rw-r--r-- | Documentation/trace/ftrace.rst | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst index fdf5fb54a04c..e45f0786f3f9 100644 --- a/Documentation/trace/ftrace.rst +++ b/Documentation/trace/ftrace.rst @@ -543,6 +543,30 @@ of ftrace. Here is a list of some of the key files: See events.txt for more information. + timestamp_mode: + + Certain tracers may change the timestamp mode used when + logging trace events into the event buffer. Events with + different modes can coexist within a buffer but the mode in + effect when an event is logged determines which timestamp mode + is used for that event. The default timestamp mode is + 'delta'. + + Usual timestamp modes for tracing: + + # cat timestamp_mode + [delta] absolute + + The timestamp mode with the square brackets around it is the + one in effect. + + delta: Default timestamp mode - timestamp is a delta against + a per-buffer timestamp. + + absolute: The timestamp is a full timestamp, not a delta + against some other value. As such it takes up more + space and is less efficient. + hwlat_detector: Directory for the Hardware Latency Detector. |