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| author | Daniel Bristot de Oliveira <bristot@kernel.org> | 2021-12-10 19:11:31 +0100 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2022-01-13 17:02:43 -0500 |
| commit | 29380d4055e524de918c76a861df17d14a4b7224 (patch) | |
| tree | 1baadf70b7def2c79f21ff3a5265fd8dc57c5ab4 /Documentation/tools | |
| parent | e7041c6b3c123ef2160ff7a948e458f8241e4e03 (diff) | |
rtla: Add rtla timerlat documentation
Man page for rtla timerlat tool.
Link: https://lkml.kernel.org/r/78678b8d024bf5a3a79f831ac9441b96e8d2f56e.1639158831.git.bristot@kernel.org
Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'Documentation/tools')
| -rw-r--r-- | Documentation/tools/rtla/common_timerlat_description.rst | 10 | ||||
| -rw-r--r-- | Documentation/tools/rtla/rtla-timerlat.rst | 57 |
2 files changed, 67 insertions, 0 deletions
diff --git a/Documentation/tools/rtla/common_timerlat_description.rst b/Documentation/tools/rtla/common_timerlat_description.rst new file mode 100644 index 000000000000..321201cb8597 --- /dev/null +++ b/Documentation/tools/rtla/common_timerlat_description.rst @@ -0,0 +1,10 @@ +The **rtla timerlat** tool is an interface for the *timerlat* tracer. The +*timerlat* tracer dispatches a kernel thread per-cpu. These threads +set a periodic timer to wake themselves up and go back to sleep. After +the wakeup, they collect and generate useful information for the +debugging of operating system timer latency. + +The *timerlat* tracer outputs information in two ways. It periodically +prints the timer latency at the timer *IRQ* handler and the *Thread* +handler. It also enable the trace of the most relevant information via +**osnoise:** tracepoints. diff --git a/Documentation/tools/rtla/rtla-timerlat.rst b/Documentation/tools/rtla/rtla-timerlat.rst new file mode 100644 index 000000000000..44a49e6f302b --- /dev/null +++ b/Documentation/tools/rtla/rtla-timerlat.rst @@ -0,0 +1,57 @@ +================ +rtla-timerlat +================ +------------------------------------------- +Measures the operating system timer latency +------------------------------------------- + +:Manual section: 1 + +SYNOPSIS +======== +**rtla timerlat** [*MODE*] ... + +DESCRIPTION +=========== + +.. include:: common_timerlat_description.rst + +The *timerlat* tracer outputs information in two ways. It periodically +prints the timer latency at the timer *IRQ* handler and the *Thread* handler. +It also provides information for each noise via the **osnoise:** tracepoints. +The **rtla timerlat top** mode displays a summary of the periodic output +from the *timerlat* tracer. The **rtla hist hist** mode displays a histogram +of each tracer event occurrence. For further details, please refer to the +respective man page. + +MODES +===== +**top** + + Prints the summary from *timerlat* tracer. + +**hist** + + Prints a histogram of timerlat samples. + +If no *MODE* is given, the top mode is called, passing the arguments. + +OPTIONS +======= +**-h**, **--help** + + Display the help text. + +For other options, see the man page for the corresponding mode. + +SEE ALSO +======== +**rtla-timerlat-top**\(1), **rtla-timerlat-hist**\(1) + +*timerlat* tracer documentation: <https://www.kernel.org/doc/html/latest/trace/timerlat-tracer.html> + +AUTHOR +====== +Written by Daniel Bristot de Oliveira <bristot@kernel.org> + +.. include:: common_appendix.rst |