linux/Documentation/tools/rtla/rtla-timerlat-hist.rst
Daniel Bristot de Oliveira 2091336b9a rtla/timerlat_hist: Add auto-analysis support
Add auto-analysis to timerlat hist, including the --no-aa option to
reduce overhead and --dump-task. --aa-only was not added as it is
already on timerlat top.

Link: https://lkml.kernel.org/r/c2693f47ee83e659a7723fed8035f5d2534f528e.1686066600.git.bristot@kernel.org

Cc: William White <chwhite@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-13 16:35:46 -04:00

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=====================
rtla-timerlat-hist
=====================
------------------------------------------------
Histograms of the operating system timer latency
------------------------------------------------
:Manual section: 1
SYNOPSIS
========
**rtla timerlat hist** [*OPTIONS*] ...
DESCRIPTION
===========
.. include:: common_timerlat_description.rst
The **rtla timerlat hist** displays a histogram of each tracer event
occurrence. This tool uses the periodic information, and the
**osnoise:** tracepoints are enabled when using the **-T** option.
OPTIONS
=======
.. include:: common_timerlat_options.rst
.. include:: common_hist_options.rst
.. include:: common_options.rst
.. include:: common_timerlat_aa.rst
EXAMPLE
=======
In the example below, **rtla timerlat hist** is set to run for *10* minutes,
in the cpus *0-4*, *skipping zero* only lines. Moreover, **rtla timerlat
hist** will change the priority of the *timerlat* threads to run under
*SCHED_DEADLINE* priority, with a *10us* runtime every *1ms* period. The
*1ms* period is also passed to the *timerlat* tracer. Auto-analysis is disabled
to reduce overhead ::
[root@alien ~]# timerlat hist -d 10m -c 0-4 -P d:100us:1ms -p 1ms --no-aa
# RTLA timerlat histogram
# Time unit is microseconds (us)
# Duration: 0 00:10:00
Index IRQ-000 Thr-000 IRQ-001 Thr-001 IRQ-002 Thr-002 IRQ-003 Thr-003 IRQ-004 Thr-004
0 276489 0 206089 0 466018 0 481102 0 205546 0
1 318327 35487 388149 30024 94531 48382 83082 71078 388026 55730
2 3282 122584 4019 126527 28231 109012 23311 89309 4568 98739
3 940 11815 837 9863 6209 16227 6895 17196 910 9780
4 444 17287 424 11574 2097 38443 2169 36736 462 13476
5 206 43291 255 25581 1223 101908 1304 101137 236 28913
6 132 101501 96 64584 635 213774 757 215471 99 73453
7 74 169347 65 124758 350 57466 441 53639 69 148573
8 53 85183 31 156751 229 9052 306 9026 39 139907
9 22 10387 12 42762 161 2554 225 2689 19 26192
10 13 1898 8 5770 114 1247 128 1405 13 3772
11 9 560 9 924 71 686 76 765 8 713
12 4 256 2 360 50 411 64 474 3 278
13 2 167 2 172 43 256 53 350 4 180
14 1 88 1 116 15 198 42 223 0 115
15 2 63 3 94 11 139 20 150 0 58
16 2 37 0 56 5 78 10 102 0 39
17 0 18 0 28 4 57 8 80 0 15
18 0 8 0 17 2 50 6 56 0 12
19 0 9 0 5 0 19 0 48 0 18
20 0 4 0 8 0 11 2 27 0 4
21 0 2 0 3 1 9 1 18 0 6
22 0 1 0 3 1 7 0 3 0 5
23 0 2 0 4 0 2 0 7 0 2
24 0 2 0 2 1 3 0 3 0 5
25 0 0 0 1 0 1 0 1 0 3
26 0 1 0 0 0 2 0 2 0 0
27 0 0 0 3 0 1 0 0 0 1
28 0 0 0 3 0 0 0 1 0 0
29 0 0 0 2 0 2 0 1 0 3
30 0 1 0 0 0 0 0 0 0 0
31 0 1 0 0 0 0 0 2 0 2
32 0 0 0 1 0 2 0 0 0 0
33 0 0 0 2 0 0 0 0 0 1
34 0 0 0 0 0 0 0 0 0 2
35 0 1 0 1 0 0 0 0 0 1
36 0 1 0 0 0 1 0 1 0 0
37 0 0 0 1 0 0 0 0 0 0
40 0 0 0 0 0 1 0 1 0 0
41 0 0 0 0 0 0 0 0 0 1
42 0 0 0 0 0 0 0 0 0 1
44 0 0 0 0 0 1 0 0 0 0
46 0 0 0 0 0 0 0 1 0 0
47 0 0 0 0 0 0 0 0 0 1
50 0 0 0 0 0 0 0 0 0 1
54 0 0 0 1 0 0 0 0 0 0
58 0 0 0 1 0 0 0 0 0 0
over: 0 0 0 0 0 0 0 0 0 0
count: 600002 600002 600002 600002 600002 600002 600002 600002 600002 600002
min: 0 1 0 1 0 1 0 1 0 1
avg: 0 5 0 5 0 4 0 4 0 5
max: 16 36 15 58 24 44 21 46 13 50
SEE ALSO
========
**rtla-timerlat**\(1), **rtla-timerlat-top**\(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>