kernel/linux.git/tools/tracing/rtla/src/actions.h, branch v7.1

rtla: Exit on memory allocation failures during initialization

2026-03-10T09:32:37+00:00

Most memory allocations in rtla happen during early initialization before any resources are acquired that would require cleanup. In these cases, propagating allocation errors just adds complexity without any benefit. There's nothing to clean up, and the program must exit anyway. This patch introduces fatal allocation wrappers (calloc_fatal, reallocarray_fatal, strdup_fatal) that call fatal() on allocation failure. These wrappers simplify the code by eliminating unnecessary error propagation paths. The patch converts early allocations to use these wrappers in actions_init() and related action functions, osnoise_context_alloc() and osnoise_init_tool(), trace_instance_init() and trace event functions, and parameter structure allocations in main functions. This simplifies the code while maintaining the same behavior: immediate exit on allocation failure during initialization. Allocations that require cleanup, such as those in histogram allocation functions with goto cleanup paths, are left unchanged and continue to return errors. Signed-off-by: Wander Lairson Costa Link: https://lore.kernel.org/r/20260309195040.1019085-2-wander@redhat.com Signed-off-by: Tomas Glozar

rtla: Introduce for_each_action() helper

2026-01-07T14:57:55+00:00

The for loop to iterate over the list of actions is used in more than one place. To avoid code duplication and improve readability, introduce a for_each_action() helper macro. Replace the open-coded for loops with the new helper. Signed-off-by: Wander Lairson Costa Link: https://lore.kernel.org/r/20260106133655.249887-4-wander@redhat.com Signed-off-by: Tomas Glozar

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)

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)