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authorLinus Torvalds <torvalds@linux-foundation.org>2022-03-23 21:08:10 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-03-23 21:08:10 +0300
commit20f463fb38686dd3fe7e6903cab56bdbbf756238 (patch)
tree8747e99874018eff5f5de82155f1ddc3512a07fa /Documentation
parent3ef4ea3d84ca568dcd57816b9521e82e3bd94f08 (diff)
parent75016ca3acd0de79868ef5b0694195fe05288ade (diff)
downloadlinux-20f463fb38686dd3fe7e6903cab56bdbbf756238.tar.xz
Merge tag 'trace-rtla-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull RTLA tracing tool updates from Steven Rostedt: "Real Time Analysis Tool updatesfor 5.18: - Support for adjusting tracing_threashold - Add -a (auto) option to make it easier for users to debug in the field - Add -e option to add more events to the trace - Add --trigger option to add triggers to events - Add --filter option to filter events - Add support to save histograms to the file - Add --dma-latency to set /dev/cpu_dma_latency - Other fixes and cleanups" * tag 'trace-rtla-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: rtla: Tools main loop cleanup rtla/timerlat: Add --dma-latency option rtla/osnoise: Fix osnoise hist stop tracing message rtla: Check for trace off also in the trace instance rtla/trace: Save event histogram output to a file rtla: Add --filter support rtla/trace: Add trace event filter helpers rtla: Add --trigger support rtla/trace: Add trace event trigger helpers rtla: Add -e/--event support rtla/trace: Add trace events helpers rtla/timerlat: Add the automatic trace option rtla/osnoise: Add the automatic trace option rtla/osnoise: Add an option to set the threshold rtla/osnoise: Add support to adjust the tracing_thresh
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/tools/rtla/common_options.rst19
-rw-r--r--Documentation/tools/rtla/common_osnoise_options.rst10
-rw-r--r--Documentation/tools/rtla/common_timerlat_options.rst12
3 files changed, 41 insertions, 0 deletions
diff --git a/Documentation/tools/rtla/common_options.rst b/Documentation/tools/rtla/common_options.rst
index 721790ad984e..af76df6205d4 100644
--- a/Documentation/tools/rtla/common_options.rst
+++ b/Documentation/tools/rtla/common_options.rst
@@ -14,6 +14,25 @@
Save the stopped trace to [*file|osnoise_trace.txt*].
+**-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:
diff --git a/Documentation/tools/rtla/common_osnoise_options.rst b/Documentation/tools/rtla/common_osnoise_options.rst
index d556883e4e26..f792ca58c211 100644
--- a/Documentation/tools/rtla/common_osnoise_options.rst
+++ b/Documentation/tools/rtla/common_osnoise_options.rst
@@ -1,3 +1,8 @@
+**-a**, **--auto** *us*
+
+ Set the automatic trace mode. This mode sets some commonly used options
+ while debugging the system. It is equivalent to use **-s** *us* **-T 1 -t**.
+
**-p**, **--period** *us*
Set the *osnoise* tracer period in microseconds.
@@ -15,3 +20,8 @@
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.
+
+**-T**, **--threshold** *us*
+
+ Specify the minimum delta between two time reads to be considered noise.
+ The default threshold is *5 us*.
diff --git a/Documentation/tools/rtla/common_timerlat_options.rst b/Documentation/tools/rtla/common_timerlat_options.rst
index e9c1bfd55d48..bacdea6de7a3 100644
--- a/Documentation/tools/rtla/common_timerlat_options.rst
+++ b/Documentation/tools/rtla/common_timerlat_options.rst
@@ -1,3 +1,10 @@
+**-a**, **--auto** *us*
+
+ Set the automatic trace mode. This mode sets some commonly used options
+ while debugging the system. It is equivalent to use **-T** *us* **-s** *us*
+ **-t**. By default, *timerlat* tracer uses FIFO:95 for *timerlat* threads,
+ thus equilavent to **-P** *f:95*.
+
**-p**, **--period** *us*
Set the *timerlat* tracer period in microseconds.
@@ -14,3 +21,8 @@
Save the stack trace at the *IRQ* if a *Thread* latency is higher than the
argument in us.
+
+**--dma-latency** *us*
+ Set the /dev/cpu_dma_latency to *us*, aiming to bound exit from idle latencies.
+ *cyclictest* sets this value to *0* by default, use **--dma-latency** *0* to have
+ similar results.