Man page for rtla osnoise top mode. Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Tom Zanussi <zanussi@xxxxxxxxxx> Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Cc: Juri Lelli <juri.lelli@xxxxxxxxxx> Cc: Clark Williams <williams@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Cc: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx> Cc: linux-rt-users@xxxxxxxxxxxxxxx Cc: linux-trace-devel@xxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx Signed-off-by: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx> --- .../rtla/Documentation/rtla-osnoise-top.txt | 98 +++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 tools/tracing/rtla/Documentation/rtla-osnoise-top.txt diff --git a/tools/tracing/rtla/Documentation/rtla-osnoise-top.txt b/tools/tracing/rtla/Documentation/rtla-osnoise-top.txt new file mode 100644 index 000000000000..c7c0e7983c6f --- /dev/null +++ b/tools/tracing/rtla/Documentation/rtla-osnoise-top.txt @@ -0,0 +1,98 @@ +rtla-osnoise-top(1) +=================== + +NAME +---- +rtla-osnoise-top - Display a summary of the operating system noise + +SYNOPSIS +-------- +*rtla osnoise top* ['OPTIONS'] + +DESCRIPTION +----------- +The rtla-osnoise-top(1) tool is an interface for the osnoise tracer. The +osnoise tracer dispatches a kernel thread per-cpu. These threads read the +time in a loop while with preemption, softirq and IRQs enabled, thus +allowing all the sources of osnoise during its execution. The osnoise's +tracer threads take note of the delta between each time read, along with +an interference counter for each source of interference. At the end of +each period, the osnoise tracer displays a summary of the results. + +*rtla osnoise top* collects the periodic summary from the osnoise tracer, +including the counters of the occurrence of the interference source, +displaying the results in a user-friendly format. + +The tool also allows many configurations of the osnoise tracer and the +collection of the tracer output. + +OPTIONS +------- +*-h*, *--help*:: +Print help menu. +*-p*, *--period* 'us':: +Set the osnoise tracer period in microseconds. +*-r*, *--runtime* 'us':: +Set the osnoise tracer runtime in microseconds. +*-s*, *--stop* 'us':: +Stop the trace if a single sample is higher than the argument in microseconds. +If -T is set, it will also save the trace to the output. +*-S*, *--stop-total* 'us':: +Stop the trace if the total sample is higher than the argument in microseconds. +If -T is set, it will also save the trace to the output. +*-c*, *--cpus* 'cpu-list':: +Set the osnoise tracer to run the sample threads in the cpu-list. +*-d*, *--duration* 'time[s|m|h|d]':: +Set the duration of the session. +*-t*, *--trace*['=file']:: +Save the stopped trace to ['file|osnoise_trace.txt']. +*-q*, *--quiet*:: +Print only a summary at the end of the session. +*-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. + +EXAMPLE +------- +In the example below, the rtla osnoise top tool is set to run with a +real-time priority 'FIFO:1', on CPUs '0-3', for '900ms' at each period +('1s' by default). The reason for reducing the runtime is to avoid starving +the rtla tool. The tool is also set to run for 'one minute' and to display +a summary of the report at the end of the session. + +------------------------------------------------------- +[root@f34 ~]# rtla osnoise top -P F:1 -c 0-3 -r 900000 -d 1M -q + Operating System Noise +duration: 0 00:01:00 | time is in us +CPU Period Runtime Noise % CPU Aval Max Noise Max Single HW NMI IRQ Softirq Thread + 0 #59 53100000 304896 99.42580 6978 56 549 0 53111 1590 13 + 1 #59 53100000 338339 99.36282 8092 24 399 0 53130 1448 31 + 2 #59 53100000 290842 99.45227 6582 39 855 0 53110 1406 12 + 3 #59 53100000 204935 99.61405 6251 33 290 0 53156 1460 12 +------------------------------------------------------- + +SEE ALSO +-------- +_rtla-osnoise(1)_, _rtla-osnoise-hist_(1) + +Osnoise tracer documentation: <https://www.kernel.org/doc/html/latest/trace/osnoise-tracer.html> + +AUTHOR +------ +Written by Daniel Bristot de Oliveira <bristot@xxxxxxxxxx> + +REPORTING BUGS +-------------- +Report bugs to <lkml@xxxxxxxxxxxxxxx> + +LICENSE +------- +rtla is Free Software licensed under the GNU GPLv2 + +COPYING +------- +Copyright \(C) 2021 Red Hat, Inc. Free use of this software is granted under +the terms of the GNU Public License (GPL). -- 2.31.1