doc/man/lttng-add-context.1.txt

   1 lttng-add-context(1)
   2 ====================
   3
   4
   5 NAME
   6 ----
   7 lttng-add-context - Add context fields to an LTTng channel
   8
   9
  10 SYNOPSIS
  11 --------
  12 Add context fields to a channel:
  13
  14 [verse]
  15 *lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *add-context*
  16       (option:--kernel | option:--userspace | option:--jul | option:--log4j)
  17       [option:--session='SESSION'] [option:--channel='CHANNEL']
  18       option:--type='TYPE' [option:--type='TYPE']...
  19
  20 List the available context fields:
  21
  22 [verse]
  23 *lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *add-context* option:--list
  24
  25
  26 DESCRIPTION
  27 -----------
  28 The `lttng add-context` command adds one or more context fields to a
  29 channel.
  30
  31 Channels are created with the man:lttng-enable-channel(1) command.
  32
  33 When context fields are added to a channel, all the events emitted
  34 within this channel contain the dynamic values of those context fields.
  35
  36 If the option:--session option is omitted, the current tracing session
  37 is used. If the option:--channel option is omitted, the context fields
  38 are added to all the selected tracing session's channels.
  39
  40 Many context fields can be added to a channel at once by repeating the
  41 option:--type option.
  42
  43 perf counters are available as per-CPU (`perf:cpu:` prefix) as well as
  44 per-thread (`perf:thread:` prefix) counters. Currently, per-CPU counters
  45 can only be used in the Linux kernel tracing domain, while per-thread
  46 counters can only be used in the user space tracing domain.
  47
  48 It is also possible to enable PMU counters by raw ID using the
  49 `perf:cpu:raw:r<N>:<name>` or `perf:thread:raw:r<N>:<name>` format for
  50 the kernel and user-space respectively. `<N>` is a hexadecimal event
  51 descriptor which is the same format as used by perf-record(1): a
  52 concatenation of the `Umask value` and `Event number` provided by the
  53 processor's manufacturer. The possible values for this field are
  54 processor-specific. The `<name>` field is used to associate a clearer
  55 name to the counter.
  56
  57 Application-specific context fields can be added to a channel using the
  58 following syntax:
  59
  60 [verse]
  61 $app.'PROVIDER':__TYPE__
  62
  63 with:
  64
  65 'PROVIDER'::
  66     Provider name.
  67
  68 'TYPE'::
  69     Context type name.
  70
  71 NOTE: Make sure to **single-quote** the type when running the command
  72 from a shell, as `$` is a special character for variable substitution in
  73 most shells.
  74
  75 Use the option:--list option without other arguments to list the
  76 available context field names.
  77
  78
  79 include::common-cmd-options-head.txt[]
  80
  81
  82 Domain
  83 ~~~~~~
  84 One of:
  85
  86 option:-j, option:--jul::
  87     Add context to channel in the `java.util.logging` (JUL) domain.
  88
  89 option:-k, option:--kernel::
  90     Add context to channel in the Linux kernel domain.
  91
  92 option:-l, option:--log4j::
  93     Add context to channel in the Apache log4j domain.
  94
  95 option:-u, option:--userspace::
  96     Add context to channel in the user space domain.
  97
  98
  99 Target
 100 ~~~~~~
 101 option:-c, option:--channel='CHANNEL'::
 102     Add context fields to a channel named 'CHANNEL' instead of adding
 103     them to all the channels.
 104
 105 option:-s, option:--session='SESSION'::
 106     Add context fields to a channel in the tracing session named 'SESSION'
 107     instead of the current tracing session.
 108
 109
 110 Context
 111 ~~~~~~~
 112 option:--list::
 113     List the available context fields. Use this option alone.
 114
 115 option:-t, option:--type='TYPE'::
 116     Add context field named 'TYPE'. This option can be repeated as
 117     many times as needed on the command-line.
 118
 119
 120 include::common-cmd-help-options.txt[]
 121
 122
 123 include::common-cmd-footer.txt[]
 124
 125
 126 SEE ALSO
 127 --------
 128 man:lttng(1)