lttng-add-map(1)
================
:revdate: 30 Mars 2021


NAME
----
lttng-add-map - Create LTTng map


SYNOPSIS
--------

Create a Linux kernel map:
[verse]
*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *add-map* option:--kernel
      [option:--session='SESSION'] [--bitness='BITNESS']
      [option:--coalesce-hits]
      [option:--may-key-count='MAX_KEY_COUNT']
      'MAP'

Create a user space map:
[verse]
*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *add-map* option:--userspace
      [option:--session='SESSION'] [--bitness='BITNESS']
      [(option:--per-pid | option:--per-uid)]
      [option:--coalesce-hits]
      [option:--may-key-count='MAX_KEY_COUNT']
      'MAP'


DESCRIPTION
-----------

The `lttng add-map` command is used to create maps.

A map is key-value data structure used to count events occurences. When
creating a map, many parameters related to this data structure can be
fine-tuned.

When 'MAP' does not name an existing map, a map named
'MAP' is created.

OPTIONS
-------

option:-k, option:--kernel::
    Create map in the Linux kernel domain.

option:-u, option:--userspace::
    Create map in the user space domain.

option:-s 'SESSION', option:--session='SESSION'::
    Create map in the tracing session named 'SESSION'
    instead of the current tracing session.

option:--bitness='BITNESS'::
    Set the counter bucket size to BITNESS bits.

option:--coalesce-hits::
    Coalesces hits from identical event rules.

option:--per-pid::
    Keep one event counter per process.

option:--per-uid::
    Keep one event counter for all processes of a single user.

include::common-cmd-help-options.txt[]

include::common-cmd-footer.txt[]


SEE ALSO
--------
man:lttng-enable-map(1),
man:lttng-disable-map(1),
man:lttng-view-map(1),
man:lttng-list(1),
man:lttng-add-trigger(1),
man:lttng(1)