linux.git/Documentation/tools/rtla/common_appendix.txt, branch v7.2

rtla: Parse cmdline using libsubcmd

2026-05-28T11:02:48+00:00

Instead of using getopt_long() directly to parse the command line
arguments given to an RTLA tool, use libsubcmd's parse_options().

Utilizing libsubcmd for parsing command line arguments has several
benefits:

- A help message is automatically generated by libsubcmd from the
  specification, removing the need of writing it by hand.
- Options are sorted into groups based on which part of tracing (CPU,
  thread, auto-analysis, tuning, histogram) they relate to.
- Common parsing patterns for numerical and boolean values now share
  code, with the target variable being stored in the option array.

To avoid duplication of the option parsing logic, RTLA-specific
macros defining struct option values are created:

- RTLA_OPT_* for options common to all tools
- OSNOISE_OPT_* and TIMERLAT_OPT_* for options specific to
  osnoise/timerlat tools
- HIST_OPT_* macros for options specific to histogram-based tools.

Individual *_parse_args() functions then construct an array out of
these macros that is then passed to libsubcmd's parse_options().

All code specific to command line options parsing is moved out of the
individual tool files into a new file, cli.c, which also contains the
contents of the rtla.c file. A private header, cli_p.h, is added
alongside the public header cli.h, so that unit tests are able to test
statically declared option callbacks.

Minor changes:

- The return value of tool-level help option changes to 129, as this is
  the value set by libsubcmd; this is reflected in affected test cases.
  The implementation of help for command-level and tracer-level help
  is set to 129 as well for consistency, and the change is reflected in
  exit value documentation.
- Related to the above, {rtla,osnoise,timerlat}_usage() are marked
  __noreturn and exit() is removed from after they are called for
  cleaner code.
- The error messages for invalid argument for options --dma-latency and
  -E/--entries were corrected, fixing off-by-one in the limits.

Note that unsetting options (using --no- syntax) is currently not
implemented for options that use custom callbacks. For --irq and
--thread, it will never be implemented, as they conflict with already
existing --no-irq and --no-thread with a different meaning.

Assisted-by: Composer:composer-1.5
Link: https://lore.kernel.org/r/20260528103254.2990068-5-tglozar@redhat.com
Signed-off-by: Tomas Glozar

Documentation/rtla: Document SIGINT behavior

2026-03-27T09:58:30+00:00

The behavior of RTLA on receiving SIGINT is currently undocumented.

Describe it in RTLA's common appendix that appears in man pages for all
RTLA tools to avoid confusion.

Suggested-by: Attila Fazekas 
Reviewed-by: Steven Rostedt (Google) 
Link: https://lore.kernel.org/r/20260324123229.152424-1-tglozar@redhat.com
Signed-off-by: Tomas Glozar

Documentation/rtla: rename common_xxx.rst files to common_xxx.txt

2025-10-17T20:25:12+00:00

Sphinx reports htmldocs errors:

Documentation/tools/rtla/common_options.rst:58: ERROR: Undefined substitution referenced: "threshold".
Documentation/tools/rtla/common_options.rst:88: ERROR: Undefined substitution referenced: "tool".
Documentation/tools/rtla/common_options.rst:88: ERROR: Undefined substitution referenced: "thresharg".
Documentation/tools/rtla/common_options.rst:88: ERROR: Undefined substitution referenced: "tracer".
Documentation/tools/rtla/common_options.rst:92: ERROR: Undefined substitution referenced: "tracer".
Documentation/tools/rtla/common_options.rst:98: ERROR: Undefined substitution referenced: "actionsperf".
Documentation/tools/rtla/common_options.rst:113: ERROR: Undefined substitution referenced: "tool".

common_*.rst files are snippets that are intended to be included by rtla
docs (rtla*.rst). common_options.rst in particular contains
substitutions which depend on other common_* includes, so building it
independently as reST source results in above errors.

Rename all common_*.rst files to common_*.txt to prevent Sphinx from
building these snippets as standalone reST source and update all include
references accordingly.

Link: https://www.sphinx-doc.org/en/master/usage/restructuredtext/basics.html#substitutions
Suggested-by: Tomas Glozar 
Suggested-by: Bagas Sanjaya 
Signed-off-by: Gopi Krishna Menon 
Reviewed-by: Tomas Glozar 
Fixes: 05b7e10687c6 ("tools/rtla: Add remaining support for osnoise actions")
Reviewed-by: Bagas Sanjaya 
Link: https://lore.kernel.org/r/20251008184522.13201-1-krishnagopi487@gmail.com
[Bagas: massage commit message and apply trailers]
Signed-off-by: Bagas Sanjaya 
Reviewed-by: Randy Dunlap 
Tested-by: Randy Dunlap 
Signed-off-by: Jonathan Corbet 
Message-ID: <20251013092719.30780-2-bagasdotme@gmail.com>