RTLA: An interface for osnoise/timerlat tracers

The rtla(1) is a meta-tool that includes a set of commands that aims to analyze the real-time properties of Linux. But instead of testing Linux as a black box, rtla leverages kernel tracing capabilities to provide precise information about the properties and root causes of unexpected results.

To start, it presents an interface to the osnoise and timerlat tracers. In the future, it will also serve as home to the rtsl [1] and other latency/noise tracers.

If you just want to run it, you can download the tarball here:
- https://bristot.me/files/rtla/tarball/rtla-0.5.tar.bz2

To compile rtla on fedora you need:

  $ git clone git://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git
  $ cd libtraceevent/
  $ make
  $ sudo make install
  $ cd ..
  $ git clone git://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git
  $ cd libtracefs/
  $ make
  $ sudo make install
  $ cd ..
  $ sudo dnf install python3-docutils procps-devel
  $ cd $rtla_src
  $ make
  $ sudo make install

The tracing option (-t) depends some kernel patches that are available at [2].

This tool was be discussed at the RT-MC during LPC2021 [3]

[1] rtsl: https://github.com/bristot/rtsl/
[2] https://lore.kernel.org/lkml/[email protected]/
[3] https://youtu.be/cZUzc0U1jJ4

Changes from V8:
- Fixed usage messages (Tao Zhou)
- Fixed some return value check on osnoise.c (Tao Zhou)
- Properly delete instances when failing to set priorities (Tao Zhou)
- Use tracefs helpers to read/write to files on osnoise.c (Steven)
Changes from V7:
- Add README.txt with information about how to compile the tool (Steven)
- Use $$($(PKG_CONFIG) --libs libtracefs) to find libtracefs on Makefile (Steven)
- Fix *buffer[4096] (using buffer[4096]) on save_trace_to_file() (Steven)
Changes from v6:
- Revisited osnoise option config functions
- Properly handles offline CPUs
- Some cleanups
- Fixed an histogram allocation problem (Tao Zhou)
- Revisited open()/read()/write() (Tao Zhou)
Changes from v5:
- Fix retval check in save_trace_to_file() (Tao Zhou)
- Fix goto logic in save_trace_to_file() (Tao Zhou)
- Removed unused save_trace_pipe_to_file() function
- Correctly handle an error on osnoise_set_* functions during "apply config" for all tools (Tao Zhou)
Changes from v3:
- Add cross-compile support (Ahmed S. Darwish)
- Move documentation to Documentation/tools/rtla (Jonathan Corbet)
- Use .rst format for documentation (Jonathan Corbet)
- Use include option from .rst to group common parts of the documentation
- Makefile (main and doc) cleanups
Changes from v2:
- Fix the miss conception of the "size" for kernel histograms (Steven/Tom)
- Change the --skip-zeros to --with-zeros option as the former is better for humans (and the latter for computers to plot charts).
- A lot of checkpatch fixes for the user-space part.
Changes from v1:
- Fixes -t options on osnoise tracers (-t means --trace for all tools now)
- Fixes --bucket-size references (not --bucket_size)
Daniel Bristot de Oliveira (14):
rtla: Real-Time Linux Analysis tool
rtla: Helper functions for rtla
rtla: Add osnoise tool
rtla/osnoise: Add osnoise top mode
rtla/osnoise: Add the hist mode
rtla: Add timerlat tool and timelart top mode
rtla/timerlat: Add timerlat hist mode
rtla: Add Documentation
rtla: Add rtla osnoise man page
rtla: Add rtla osnoise top documentation
rtla: Add rtla osnoise hist documentation
rtla: Add rtla timerlat documentation
rtla: Add rtla timerlat top documentation
rtla: Add rtla timerlat hist documentation

 Documentation/tools/rtla/Makefile             |  41 +
 Documentation/tools/rtla/common_appendix.rst  |  12 +
 .../tools/rtla/common_hist_options.rst        |  23 +
 Documentation/tools/rtla/common_options.rst   |  28 +
 .../tools/rtla/common_osnoise_description.rst |   8 +
 .../tools/rtla/common_osnoise_options.rst     |  17 +
 .../rtla/common_timerlat_description.rst      |  10 +
 .../tools/rtla/common_timerlat_options.rst    |  16 +
 .../tools/rtla/common_top_options.rst         |   3 +
 .../tools/rtla/rtla-osnoise-hist.rst          |  66 ++
 Documentation/tools/rtla/rtla-osnoise-top.rst |  61 ++
 Documentation/tools/rtla/rtla-osnoise.rst     |  59 ++
 .../tools/rtla/rtla-timerlat-hist.rst         | 106 +++
 .../tools/rtla/rtla-timerlat-top.rst          | 145 +++
 Documentation/tools/rtla/rtla-timerlat.rst    |  57 ++
 Documentation/tools/rtla/rtla.rst             |  48 +
 tools/tracing/rtla/Makefile                   | 102 ++
 tools/tracing/rtla/README.txt                 |  36 +
 tools/tracing/rtla/src/osnoise.c              | 875 ++++++++++++++++++
 tools/tracing/rtla/src/osnoise.h              |  91 ++
 tools/tracing/rtla/src/osnoise_hist.c         | 801 ++++++++++++++++
 tools/tracing/rtla/src/osnoise_top.c          | 579 ++++++++++++
 tools/tracing/rtla/src/rtla.c                 |  87 ++
 tools/tracing/rtla/src/timerlat.c             |  72 ++
 tools/tracing/rtla/src/timerlat.h             |   4 +
 tools/tracing/rtla/src/timerlat_hist.c        | 822 ++++++++++++++++
 tools/tracing/rtla/src/timerlat_top.c         | 618 +++++++++++++
 tools/tracing/rtla/src/trace.c                | 192 ++++
 tools/tracing/rtla/src/trace.h                |  27 +
 tools/tracing/rtla/src/utils.c                | 433 +++++++++
 tools/tracing/rtla/src/utils.h                |  56 ++
 31 files changed, 5495 insertions(+)
 create mode 100644 Documentation/tools/rtla/Makefile
 create mode 100644 Documentation/tools/rtla/common_appendix.rst
 create mode 100644 Documentation/tools/rtla/common_hist_options.rst
 create mode 100644 Documentation/tools/rtla/common_options.rst
 create mode 100644 Documentation/tools/rtla/common_osnoise_description.rst
 create mode 100644 Documentation/tools/rtla/common_osnoise_options.rst
 create mode 100644 Documentation/tools/rtla/common_timerlat_description.rst
 create mode 100644 Documentation/tools/rtla/common_timerlat_options.rst
 create mode 100644 Documentation/tools/rtla/common_top_options.rst
 create mode 100644 Documentation/tools/rtla/rtla-osnoise-hist.rst
 create mode 100644 Documentation/tools/rtla/rtla-osnoise-top.rst
 create mode 100644 Documentation/tools/rtla/rtla-osnoise.rst
 create mode 100644 Documentation/tools/rtla/rtla-timerlat-hist.rst
 create mode 100644 Documentation/tools/rtla/rtla-timerlat-top.rst
 create mode 100644 Documentation/tools/rtla/rtla-timerlat.rst
 create mode 100644 Documentation/tools/rtla/rtla.rst
 create mode 100644 tools/tracing/rtla/Makefile
 create mode 100644 tools/tracing/rtla/README.txt
 create mode 100644 tools/tracing/rtla/src/osnoise.c
 create mode 100644 tools/tracing/rtla/src/osnoise.h
 create mode 100644 tools/tracing/rtla/src/osnoise_hist.c
 create mode 100644 tools/tracing/rtla/src/osnoise_top.c
 create mode 100644 tools/tracing/rtla/src/rtla.c
 create mode 100644 tools/tracing/rtla/src/timerlat.c
 create mode 100644 tools/tracing/rtla/src/timerlat.h
 create mode 100644 tools/tracing/rtla/src/timerlat_hist.c
 create mode 100644 tools/tracing/rtla/src/timerlat_top.c
 create mode 100644 tools/tracing/rtla/src/trace.c
 create mode 100644 tools/tracing/rtla/src/trace.h
 create mode 100644 tools/tracing/rtla/src/utils.c
 create mode 100644 tools/tracing/rtla/src/utils.h

2.31.1