kernel/linux.git/tools/tracing/rtla/src/timerlat_hist.c, branch v6.18.21

rtla: Fix -a overriding -t argument

2025-12-18T13:03:10+00:00

[ Upstream commit ddb6e42494e5c48c17e64f29b7674b9add486a19 ] When running rtla as `rtla -t custom_file.txt -a 100` -a options override trace output filename specified by -t option. Running the command above will create _trace.txt file instead of custom_file.txt. Fix this by making sure that -a option does not override trace output filename even if it's passed after trace output filename is specified. Fixes: 173a3b014827 ("rtla/timerlat: Add the automatic trace option") Signed-off-by: Ivan Pravdin Reviewed-by: Tomas Glozar Link: https://lore.kernel.org/r/b6ae60424050b2c1c8709e18759adead6012b971.1762186418.git.ipravdin.official@gmail.com [ use capital letter in subject, as required by tracing subsystem ] Signed-off-by: Tomas Glozar Signed-off-by: Sasha Levin

tools/rtla: Add remaining support for osnoise actions

2025-09-27T08:53:48+00:00

The basic functionality came with the consolidation; now hook up the command line options, and add documentation and tests. Cc: John Kacur Cc: Costa Shulyupin Link: https://lore.kernel.org/20250907022325.243930-8-crwood@redhat.com Reviewed-by: Tomas Glozar Signed-off-by: Crystal Wood Signed-off-by: Steven Rostedt (Google)

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)

rtla/timerlat: Add continue action

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

Introduce option to resume tracing after a latency threshold overflow. The option is implemented as an action named "continue". Example: $ rtla timerlat top -q -T 200 -d 1s --on-threshold \ exec,command="echo Threshold" --on-threshold continue Threshold Threshold Threshold Timer Latency ... The feature is supported for both hist and top. After the continue action is executed, processing of the list of actions is stopped and tracing is resumed. 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/20250626123405.1496931-5-tglozar@redhat.com Signed-off-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google)

rtla/timerlat: Add action on threshold feature

2025-07-25T20:43:56+00:00

Extend the functionality provided by the -t/--trace option, which triggers saving the contents of a tracefs buffer after tracing is stopped, to support implementing arbitrary actions. A new option, --on-threshold, is added, taking an argument that further specifies the action. Actions added in this patch are: - trace[,file=]: Saves tracefs buffer, optionally taking a filename. - signal,num=,pid=: Sends signal to process. "parent" might be specified instead of number to send signal to parent process. - shell,command=: Execute shell command. Multiple actions may be specified and will be executed in order, including multiple actions of the same type. Trace output requested via -t and -a now adds a trace action to the end of the list. If an action fails, the following actions are not executed. For example, this command: $ rtla timerlat -T 20 --on-threshold trace \ --on-threshold shell,command="grep ipi_send timerlat_trace.txt" \ --on-threshold signal,num=2,pid=parent will send signal 2 (SIGINT) to parent process, but only if saved trace contains the text "ipi_send". This way, the feature can be used for flexible reactions on latency spikes, and allows combining rtla with other tooling like perf. 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/20250626123405.1496931-3-tglozar@redhat.com Signed-off-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google)

rtla/timerlat: Introduce enum timerlat_tracing_mode

2025-07-25T20:43:56+00:00

After the introduction of BPF-based sample collection, rtla-timerlat effectively runs in one of three modes: - Pure BPF mode, with tracefs only being used to set up the timerlat tracer. Sample processing and stop on threshold are handled by BPF. - tracefs mode. BPF is unsupported or kernel is lacking the necessary trace event (osnoise:timerlat_sample). Stop on theshold is handled by timerlat tracer stopping tracing in all instances. - BPF/tracefs mixed mode - BPF is used for sample collection for top or histogram, tracefs is used for trace output and/or auto-analysis. Stop on threshold is handled both through BPF program, which stops sample collection for top/histogram and wakes up rtla, and by timerlat tracer, which stops tracing for trace output/auto-analysis instances. Add enum timerlat_tracing_mode, with three values: - TRACING_MODE_BPF - TRACING_MODE_TRACEFS - TRACING_MODE_MIXED Those represent the modes described above. A field of this type is added to struct timerlat_params, named "mode", replacing the no_bpf variable. params->mode is set in timerlat_{top,hist}_parse_args to TRACING_MODE_BPF or TRACING_MODE_MIXED based on whether trace output and/or auto-analysis is requested. timerlat_{top,hist}_main then checks if BPF is not unavailable or disabled, in that case, it sets params->mode to TRACING_MODE_TRACEFS. A condition is added to timerlat_apply_config that skips setting timerlat tracer thresholds if params->mode is TRACING_MODE_BPF (those are unnecessary, since they only turn off tracing, which is already turned off in that case, since BPF is used to collect samples). 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/20250626123405.1496931-2-tglozar@redhat.com Signed-off-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google)