-c, --cpus cpu-list

Set the osnoise tracer to run the sample threads in the cpu-list.

-H, --house-keeping cpu-list

Run rtla control threads only on the given cpu-list.

-d, --duration time[s|m|h|d]

Set the duration of the session.

-D, --debug

Print debug info.

-e, --event sys:event

Enable an event in the trace (-t) session. The argument can be a specific event, e.g., -e sched:sched_switch, or all events of a system group, e.g., -e sched. Multiple -e are allowed. It is only active when -t or -a are set.

--filter <filter>

Filter the previous -e sys:event event with <filter>. For further information about event filtering see https://www.kernel.org/doc/html/latest/trace/events.html#event-filtering.

--trigger <trigger>

Enable a trace event trigger to the previous -e sys:event. If the hist: trigger is activated, the output histogram will be automatically saved to a file named system_event_hist.txt. For example, the command:

rtla <command> <mode> -t -e osnoise:irq_noise --trigger=”hist:key=desc,duration/1000:sort=desc,duration/1000:vals=hitcount”

Will automatically save the content of the histogram associated to osnoise:irq_noise event in osnoise_irq_noise_hist.txt.

For further information about event trigger see https://www.kernel.org/doc/html/latest/trace/events.html#event-triggers.

-P, --priority o:prio|r:prio|f:prio|d:runtime:period

Set scheduling parameters to the osnoise tracer threads, the format to set the priority are:

• o:prio - use SCHED_OTHER with prio;

• r:prio - use SCHED_RR with prio;

• f:prio - use SCHED_FIFO with prio;

• d:runtime[us|ms|s]:period[us|ms|s] - use SCHED_DEADLINE with runtime and period in nanoseconds.

-C, --cgroup[=cgroup]

Set a cgroup to the tracer’s threads. If the -C option is passed without arguments, the tracer’s thread will inherit rtla’s cgroup. Otherwise, the threads will be placed on the cgroup passed to the option.

--warm-up s

After starting the workload, let it run for s seconds before starting collecting the data, allowing the system to warm-up. Statistical data generated during warm-up is discarded.

--trace-buffer-size kB

Set the per-cpu trace buffer size in kB for the tracing output.

--on-threshold action

Defines an action to be executed when tracing is stopped on a latency threshold specified by |threshold|.

Multiple --on-threshold actions may be specified, and they will be executed in the order they are provided. If any action fails, subsequent actions in the list will not be executed.

Supported actions are:

• trace[,file=<filename>]

  Saves trace output, optionally taking a filename. Alternative to -t/--trace. Note that nlike -t/--trace, specifying this multiple times will result in the trace being saved multiple times.

• signal,num=<sig>,pid=<pid>

  Sends signal to process. “parent” might be specified in place of pid to target the parent process of rtla.

• shell,command=<command>

  Execute shell command.

• continue

  Continue tracing after actions are executed instead of stopping.

Example:

$ rtla |tool| |thresharg| 20 --on-threshold trace --on-threshold shell,command=”grep ipi_send |tracer|_trace.txt” --on-threshold signal,num=2,pid=parent

This will save a trace with the default filename “|tracer|_trace.txt”, print its lines that contain the text “ipi_send” on standard output, and send signal 2 (SIGINT) to the parent process.

Performance Considerations:

|actionsperf|

--on-end action

Defines an action to be executed at the end of tracing.

Multiple --on-end actions can be specified, and they will be executed in the order they are provided. If any action fails, subsequent actions in the list will not be executed.

See the documentation for --on-threshold for the list of supported actions, with the exception that continue has no effect.

Example:

$ rtla |tool| -d 5s --on-end trace

This runs rtla with the default options, and saves trace output at the end.

-h, --help

Print help menu.