kernel/linux.git/tools/tracing/rtla/src/timerlat.h, branch v7.2-rc1

rtla/timerlat: Add -A/--aligned CLI option

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

Add a new option, -A/--aligned, that enables timerlat thread alignment implemented on the kernel-side in commit 4245bf4dc58f ("tracing/osnoise: Add option to align tlat threads"). The option takes an argument, representing alignment between timerlat threads in microseconds. The feature is modeled after the option of the same name in the cyclictest tool. Link: https://lore.kernel.org/r/20260527144928.2944472-1-tglozar@redhat.com Signed-off-by: Tomas Glozar

rtla/tests: Add unit tests for CLI option callbacks

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

In addition to testing all tool_parse_args() functions, test also all callbacks used for parsing custom option formats. The callbacks represent a middle layer between the parsing functions and utility functions dedicated to checking specific argument formats, for example, scheduling class and duration. Callback tests are run before parsing functions to make sure any issue in the former is reported before it is encountered through the latter. Tests verify both successful parsing and proper rejection of invalid inputs (via exit tests). To enable testing static callbacks, a pragma once guard is added to timerlat.h for safe inclusion by cli_p.h. Add dependency of UNIT_TESTS_IN on LIBSUBCMD_INCLUDES, as the new test file tests/unit/cli_opt_callback.c includes cli_p.h which includes subcmd/parse-options.h. Link: https://lore.kernel.org/r/20260528103254.2990068-7-tglozar@redhat.com Signed-off-by: Tomas Glozar

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/timerlat: Add --stack-format option

2026-03-04T14:51:56+00:00

In the current implementation, the auto-analysis code for printing the stack captured in the tracefs buffer of the aa instance stops at the first encountered address that cannot be resolved into a function symbol. This is not always the desired behavior on all platforms; sometimes, there might be resolvable entries after unresolvable ones, and sometimes, the user might want to inspect the raw pointers for the unresolvable entries. Add a new option, --stack-format, with three values: - truncate: stop at first unresolvable entry. This is the current behavior, and is kept as the default. - skip: skip unresolvable entries, but do not stop on them. - full: print all entries, including unresolvable ones. To make this work, the "size" field of the stack entry is now also read and used as the maximum number of entries to print, capped at 64, since that is the fixed length of the "caller" field. Link: https://lore.kernel.org/r/20260119115222.744150-1-tglozar@redhat.com Signed-off-by: Tomas Glozar

rtla/timerlat: Add --bpf-action option

2026-01-07T14:57:16+00:00

Add option --bpf-action that allows the user to attach an external BPF program that will be executed via BPF tail call on latency threshold overflow. Executing additional BPF code on latency threshold overflow allows doing low-latency and in-kernel troubleshooting of the cause of the overflow. The option takes an argument, which is a path to a BPF ELF file expected to contain a function named "action_handler" in a section named "tp/timerlat_action" (the section is necessary for libbpf to assign the correct BPF program type to it). Link: https://lore.kernel.org/r/20251126144205.331954-3-tglozar@redhat.com Signed-off-by: Tomas Glozar

tools/rtla: Consolidate code between osnoise/timerlat and hist/top

2025-09-27T08:52:57+00:00

Currently a lot of code is duplicated between the different rtla tools, making maintenance more difficult, and encouraging divergence such as features that are only implemented for certain tools even though they could be more broadly applicable. Merge the various main() functions into a common run_tool() with an ops struct for tool-specific details. Implement enough support for actions on osnoise to not need to keep the old params->trace_output path. Cc: John Kacur Cc: Costa Shulyupin Link: https://lore.kernel.org/20250907022325.243930-5-crwood@redhat.com Reviewed-by: Tomas Glozar Signed-off-by: Crystal Wood Signed-off-by: Steven Rostedt (Google)

tools/rtla: Create common_apply_config()

2025-09-27T08:52:46+00:00

Merge the common bits of osnoise_apply_config() and timerlat_apply_config(). Put the result in a new common.c, and move enough things to common.h so that common.c does not need to include osnoise.h. Cc: John Kacur Cc: Costa Shulyupin Link: https://lore.kernel.org/20250907022325.243930-4-crwood@redhat.com Reviewed-by: Tomas Glozar Signed-off-by: Crystal Wood Signed-off-by: Steven Rostedt (Google)

tools/rtla: Move top/hist params into common struct

2025-09-27T08:52:17+00:00

The hist members were very similar between timerlat and top, so just use one common hist struct. output_divisor, quiet, and pretty printing are pretty generic concepts that can go in the main struct even if not every specific tool (currently) uses them. Cc: John Kacur Cc: Costa Shulyupin Link: https://lore.kernel.org/20250907022325.243930-3-crwood@redhat.com Reviewed-by: Tomas Glozar Signed-off-by: Crystal Wood Signed-off-by: Steven Rostedt (Google)

tools/rtla: Consolidate common parameters into shared structure

2025-09-27T08:51:18+00:00

timerlat_params and osnoise_params structures contain 15 identical fields. Introduce a new header common.h and define a common_params structure to consolidate shared fields, reduce code duplication, and enhance maintainability. Cc: John Kacur Link: https://lore.kernel.org/20250907022325.243930-2-crwood@redhat.com Reviewed-by: Tomas Glozar Signed-off-by: Costa Shulyupin Signed-off-by: Crystal Wood Signed-off-by: Steven Rostedt (Google)

rtla/timerlat: Add action on end feature

2025-07-25T20:43:57+00:00

Implement actions on end next to actions on threshold. A new option, --on-end is added, parallel to --on-threshold. Instead of being executed whenever a latency threshold is reached, it is executed at the end of the measurement. For example: $ rtla timerlat hist -d 5s --on-end trace will save the trace output at the end. All actions supported by --on-threshold are also supported by --on-end, except for continue, which does nothing with --on-end. Cc: John Kacur Cc: Luis Goncalves Cc: Arnaldo Carvalho de Melo Cc: Chang Yin Cc: Costa Shulyupin Cc: Crystal Wood Cc: Gabriele Monaco Link: https://lore.kernel.org/20250626123405.1496931-6-tglozar@redhat.com Signed-off-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google)