xref: /linux/Documentation/tools/rtla/rtla-timerlat-hist.rst (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1=====================
2rtla-timerlat-hist
3=====================
4------------------------------------------------
5Histograms of the operating system timer latency
6------------------------------------------------
7
8:Manual section: 1
9
10SYNOPSIS
11========
12**rtla timerlat hist** [*OPTIONS*] ...
13
14DESCRIPTION
15===========
16
17.. include:: common_timerlat_description.rst
18
19The **rtla timerlat hist** displays a histogram of each tracer event
20occurrence. This tool uses the periodic information, and the
21**osnoise:** tracepoints are enabled when using the **-T** option.
22
23OPTIONS
24=======
25
26.. include:: common_timerlat_options.rst
27
28.. include:: common_hist_options.rst
29
30.. include:: common_options.rst
31
32.. include:: common_timerlat_aa.rst
33
34EXAMPLE
35=======
36In the example below, **rtla timerlat hist** is set to run for *10* minutes,
37in the cpus *0-4*, *skipping zero* only lines. Moreover, **rtla timerlat
38hist** will change the priority of the *timerlat* threads to run under
39*SCHED_DEADLINE* priority, with a *100us* runtime every *1ms* period. The
40*1ms* period is also passed to the *timerlat* tracer. Auto-analysis is disabled
41to reduce overhead ::
42
43  [root@alien ~]# timerlat hist -d 10m -c 0-4 -P d:100us:1ms -p 1000 --no-aa
44  # RTLA timerlat histogram
45  # Time unit is microseconds (us)
46  # Duration:   0 00:10:00
47  Index   IRQ-000   Thr-000   IRQ-001   Thr-001   IRQ-002   Thr-002   IRQ-003   Thr-003   IRQ-004   Thr-004
48  0        276489         0    206089         0    466018         0    481102         0    205546         0
49  1        318327     35487    388149     30024     94531     48382     83082     71078    388026     55730
50  2          3282    122584      4019    126527     28231    109012     23311     89309      4568     98739
51  3           940     11815       837      9863      6209     16227      6895     17196       910      9780
52  4           444     17287       424     11574      2097     38443      2169     36736       462     13476
53  5           206     43291       255     25581      1223    101908      1304    101137       236     28913
54  6           132    101501        96     64584       635    213774       757    215471        99     73453
55  7            74    169347        65    124758       350     57466       441     53639        69    148573
56  8            53     85183        31    156751       229      9052       306      9026        39    139907
57  9            22     10387        12     42762       161      2554       225      2689        19     26192
58  10           13      1898         8      5770       114      1247       128      1405        13      3772
59  11            9       560         9       924        71       686        76       765         8       713
60  12            4       256         2       360        50       411        64       474         3       278
61  13            2       167         2       172        43       256        53       350         4       180
62  14            1        88         1       116        15       198        42       223         0       115
63  15            2        63         3        94        11       139        20       150         0        58
64  16            2        37         0        56         5        78        10       102         0        39
65  17            0        18         0        28         4        57         8        80         0        15
66  18            0         8         0        17         2        50         6        56         0        12
67  19            0         9         0         5         0        19         0        48         0        18
68  20            0         4         0         8         0        11         2        27         0         4
69  21            0         2         0         3         1         9         1        18         0         6
70  22            0         1         0         3         1         7         0         3         0         5
71  23            0         2         0         4         0         2         0         7         0         2
72  24            0         2         0         2         1         3         0         3         0         5
73  25            0         0         0         1         0         1         0         1         0         3
74  26            0         1         0         0         0         2         0         2         0         0
75  27            0         0         0         3         0         1         0         0         0         1
76  28            0         0         0         3         0         0         0         1         0         0
77  29            0         0         0         2         0         2         0         1         0         3
78  30            0         1         0         0         0         0         0         0         0         0
79  31            0         1         0         0         0         0         0         2         0         2
80  32            0         0         0         1         0         2         0         0         0         0
81  33            0         0         0         2         0         0         0         0         0         1
82  34            0         0         0         0         0         0         0         0         0         2
83  35            0         1         0         1         0         0         0         0         0         1
84  36            0         1         0         0         0         1         0         1         0         0
85  37            0         0         0         1         0         0         0         0         0         0
86  40            0         0         0         0         0         1         0         1         0         0
87  41            0         0         0         0         0         0         0         0         0         1
88  42            0         0         0         0         0         0         0         0         0         1
89  44            0         0         0         0         0         1         0         0         0         0
90  46            0         0         0         0         0         0         0         1         0         0
91  47            0         0         0         0         0         0         0         0         0         1
92  50            0         0         0         0         0         0         0         0         0         1
93  54            0         0         0         1         0         0         0         0         0         0
94  58            0         0         0         1         0         0         0         0         0         0
95  over:         0         0         0         0         0         0         0         0         0         0
96  count:   600002    600002    600002    600002    600002    600002    600002    600002    600002    600002
97  min:          0         1         0         1         0         1         0         1         0         1
98  avg:          0         5         0         5         0         4         0         4         0         5
99  max:         16        36        15        58        24        44        21        46        13        50
100
101SEE ALSO
102========
103**rtla-timerlat**\(1), **rtla-timerlat-top**\(1)
104
105*timerlat* tracer documentation: <https://www.kernel.org/doc/html/latest/trace/timerlat-tracer.html>
106
107AUTHOR
108======
109Written by Daniel Bristot de Oliveira <bristot@kernel.org>
110