[PATCH 0/2] force absolute timestamp trace option

[Korben Rusek]

Normally a data event includes the delta time between itself and
the previous data event. But if a write interrupts another write
then the event cannot check the timestamp of the previous event
and so it uses a delta of 0.

Adds a new trace option: force-abs-timestamp. When this is on
each event is proceeded by an absolute timestamp event.

This follows from a discussion between jbehmer@xxxxxxxxxx
and Steven Rostedt found here:

https://lkml.org/lkml/2019/5/24/710

Korben Rusek (2):
  Add force-abs-timestamp trace option.
  tests for absolute timestamp

 Documentation/trace/ftrace.rst                |   5 +
 kernel/trace/trace.c                          |   4 +
 kernel/trace/trace.h                          |   1 +
 tools/testing/selftests/Makefile              |   1 +
 tools/testing/selftests/timestamp/Makefile    |  25 +++
 tools/testing/selftests/timestamp/abs-test.sh | 156 ++++++++++++++
 .../selftests/timestamp/abs-timestamp.c       | 198 ++++++++++++++++++
 7 files changed, 390 insertions(+)
 create mode 100644 tools/testing/selftests/timestamp/Makefile
 create mode 100644 tools/testing/selftests/timestamp/abs-test.sh
 create mode 100644 tools/testing/selftests/timestamp/abs-timestamp.c

-- 
2.27.0.290.gba653c62da-goog