linux-next.git/tools/tracing/rtla/src/rtla.c, branch master

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

rtla: Add libsubcmd dependency

2026-05-28T11:02:47+00:00

In preparation for migrating RTLA to libsubcmd, build libsubcmd from the appropriate directory next to the RTLA build proper, and link the resulting object to RTLA. libsubcmd uses str_error_r() and strlcpy() at several places. To support these, also link the respective libraries from tools/lib. For completeness, also add tools/include to include path. This will allow other userspace functions and macros shipped with the kernel to be used in RTLA; perf and bpftool, two other users of libsubcmd, already do that. To prevent a name conflict, rename RTLA's run_command() function to run_tool_command(), and replace RTLA's own container_of implementation with the one in tools/include/linux/container_of.h. Assisted-by: Composer:composer-1 Link: https://lore.kernel.org/r/20260528103254.2990068-2-tglozar@redhat.com Signed-off-by: Tomas Glozar

rtla/tests: Add unit tests for actions module

2026-05-18T09:00:52+00:00

Add unit tests covering all functions in the actions module, including both valid and invalid inputs and all action types, except for actions_perform(), where only shell and continue actions are tested. To support testing multiple modules, the unit test build was modified so that it links the entire rtla-in.o file. For this to work, the main() function in rtla.c was declared weak, so that the unit test main is able to override it. Other included minor changes to unit tests are: - Make unit test output verbose to show which tests are being run, now that we have more than 3 tests. - Add unit_tests file to .gitignore. - Split unit test sources to one file per test suite, and keep only main() function in unit_tests.c. - Fix Makefile dependencies so that "make unit-tests" will rebuild the binary with the changes in the commit. Also with the linking the entire rtla-in.o file, it now has rtla's nr_cpus symbol, so the declaration in utils unit tests is made extern. Assisted-by: Composer:composer-2-fast Link: https://lore.kernel.org/r/20260424140244.958495-1-tglozar@redhat.com Signed-off-by: Tomas Glozar

rtla: Add hwnoise tool

2023-02-14T04:56:46+00:00

The hwnoise tool is a special mode for the osnoise top tool. hwnoise dispatches the osnoise tracer and displays a summary of the noise. The difference is that it runs the tracer with the OSNOISE_IRQ_DISABLE option set, thus only allowing only hardware-related noise, resulting in a simplified output. hwnoise has the same features of osnoise. An example of the tool's output: # rtla hwnoise -c 1-11 -T 1 -d 10m -q Hardware-related Noise duration: 0 00:10:00 | time is in us CPU Period Runtime Noise % CPU Aval Max Noise Max Single HW NMI 1 #599 599000000 138 99.99997 3 3 4 74 2 #599 599000000 85 99.99998 3 3 4 75 3 #599 599000000 86 99.99998 4 3 6 75 4 #599 599000000 81 99.99998 4 4 2 75 5 #599 599000000 85 99.99998 2 2 2 75 Link: https://lkml.kernel.org/r/2d6f49a6f3a4f8b51b2c806458b1cff71ad4d014.1675805361.git.bristot@kernel.org Signed-off-by: Daniel Bristot de Oliveira Cc: Daniel Bristot de Oliveira Cc: Juri Lelli Cc: Clark Williams Cc: Bagas Sanjaya Cc: Jonathan Corbet Signed-off-by: Steven Rostedt (Google)

rtla: Fix exit status when returning from calls to usage()

2022-12-09T23:06:24+00:00

rtla_usage(), osnoise_usage() and timerlat_usage() all exit with an error status. However when these are called from help, they should exit with a non-error status. Fix this by passing the exit status to the functions. Note, although we remove the subsequent call to exit after calling usage, we leave it in at the end of a function to suppress the compiler warning "control reaches end of a non-void function". Link: https://lkml.kernel.org/r/20221107144313.22470-1-jkacur@redhat.com Signed-off-by: John Kacur Acked-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google)

rtla: Add timerlat tool and timelart top mode

2022-01-13T22:02:43+00:00

The rtla timerlat tool is an interface for the timerlat tracer. The timerlat tracer dispatches a kernel thread per-cpu. These threads set a periodic timer to wake themselves up and go back to sleep. After the wakeup, they collect and generate useful information for the debugging of operating system timer latency. The timerlat tracer outputs information in two ways. It periodically prints the timer latency at the timer IRQ handler and the Thread handler. It also provides information for each noise via the osnoise tracepoints. The rtla timerlat top mode displays a summary of the periodic output from the timerlat tracer. Here is one example of the rtla timerlat tool output: ---------- %< ---------- [root@alien ~]# rtla timerlat top -c 0-3 -d 1m Timer Latency 0 00:01:00 | IRQ Timer Latency (us) | Thread Timer Latency (us) CPU COUNT | cur min avg max | cur min avg max 0 #60001 | 0 0 0 3 | 1 1 1 6 1 #60001 | 0 0 0 3 | 2 1 1 5 2 #60001 | 0 0 1 6 | 1 1 2 7 3 #60001 | 0 0 0 7 | 1 1 1 11 ---------- >% ---------- Running: # rtla timerlat --help # rtla timerlat top --help provides information about the available options. Link: https://lkml.kernel.org/r/e95032e20c2b88c962195bf7693bb53c9ebcced8.1639158831.git.bristot@kernel.org Cc: Tao Zhou Cc: Ingo Molnar Cc: Tom Zanussi Cc: Masami Hiramatsu Cc: Juri Lelli Cc: Clark Williams Cc: John Kacur Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Sebastian Andrzej Siewior Cc: Daniel Bristot de Oliveira Cc: linux-rt-users@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt

rtla: Add osnoise tool

2022-01-13T22:02:42+00:00

The osnoise tool is the interface for the osnoise tracer. The osnoise tool will have multiple "modes" with different outputs. At this point, no mode is included. The osnoise.c includes the osnoise_context abstraction. It serves to read-save-change-restore the default values from tracing/osnoise/ directory. When the context is deleted, the default values are restored. It also includes some other helper functions for managing osnoise tracer sessions. With these bits and pieces in place, we can start adding some functionality to rtla. Link: https://lkml.kernel.org/r/2d44c21ff561f503b4c7b1813892761818118460.1639158831.git.bristot@kernel.org Cc: Tao Zhou Cc: Ingo Molnar Cc: Tom Zanussi Cc: Masami Hiramatsu Cc: Juri Lelli Cc: Clark Williams Cc: John Kacur Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Sebastian Andrzej Siewior Cc: Daniel Bristot de Oliveira Cc: linux-rt-users@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt

rtla: Real-Time Linux Analysis tool

2022-01-13T22:02:42+00:00

The rtla 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. rtla --help works and provide information about the available options. This is just the "main" and the Makefile, no function yet. Link: https://lkml.kernel.org/r/bf9118ed43a09e6c054c9a491cbe7411ad1acd89.1639158831.git.bristot@kernel.org Cc: Tao Zhou Cc: Ingo Molnar Cc: Tom Zanussi Cc: Masami Hiramatsu Cc: Juri Lelli Cc: Clark Williams Cc: John Kacur Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Sebastian Andrzej Siewior Cc: Daniel Bristot de Oliveira Cc: linux-rt-users@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt