Documentation/tools/rtla/rtla-timerlat-hist.rst


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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

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::

  [root@alien ~]# timerlat hist -d 10m -c 0-4 -P d:100us:1ms -p 1ms
  # 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>