[PATCH v3 4/4] Documentation: amd-pstate: add tracer tool introduction

Jinzhou Su
2022-03-09T01:25:02Z

Add amd pstate tracer tool introduction

Signed-off-by: Jinzhou Su <Jinzhou.Su@amd.com>
---
Documentation/admin-guide/pm/amd-pstate.rst | 26 +++++++++++++++++++++
1 file changed, 26 insertions(+)

diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst
index 2f066df4ee9c..1923cb25073b 100644
--- a/Documentation/admin-guide/pm/amd-pstate.rst
+++ b/Documentation/admin-guide/pm/amd-pstate.rst
@@ -369,6 +369,32 @@ governor (for the policies it is attached to), or by the ``CPUFreq`` core (for t
policies with other scaling governors).

+Tracer Tool
+-------------
+
+``amd_pstate_tracer.py`` can record and parse ``amd-pstate`` trace log, then
+generate performance plots. This utility can be used to debug and tune the
+performance of ``amd-pstate`` driver. The tracer tool needs to import intel
+pstate tracer.
+
+Tracer tool located in ``linux/tools/power/x86/amd_pstate_tracer``. It can be
+used in two ways. If trace file is available, then directly parse the file
+with command ::
+
+ ./amd_pstate_trace.py [-c cpus] -t <trace_file> -n <test_name>
+
+Or generate trace file with root privilege, then parse and plot with command ::
+
+ sudo ./amd_pstate_trace.py [-c cpus] -n <test_name> -i <interval> [-m kbytes]
+
+The test result can be found in ``results/test_name``. Following is the example
+about part of the output. ::
+
+ common_cpu common_secs common_usecs min_perf des_perf max_perf freq mperf apef tsc load duration_ms sample_num elapsed_time common_comm
+ CPU_005 712 116384 39 49 166 0.7565 9645075 2214891 38431470 25.1 11.646 469 2.496 kworker/5:0-40
+ CPU_006 712 116408 39 49 166 0.6769 8950227 1839034 37192089 24.06 11.272 470 2.496 kworker/6:0-1264
+
+
Reference
===========

--
2.27.0