`LTTNG_UST_TRACEPOINT_LOGLEVEL_EMERG`::
    System is unusable.

`LTTNG_UST_TRACEPOINT_LOGLEVEL_ALERT`::
    Action must be taken immediately.

`LTTNG_UST_TRACEPOINT_LOGLEVEL_CRIT`::
    Critical conditions.

`LTTNG_UST_TRACEPOINT_LOGLEVEL_ERR`::
    Error conditions.

`LTTNG_UST_TRACEPOINT_LOGLEVEL_WARNING`::
    Warning conditions.

`LTTNG_UST_TRACEPOINT_LOGLEVEL_NOTICE`::
    Normal, but significant, condition.

`LTTNG_UST_TRACEPOINT_LOGLEVEL_INFO`::
    Informational message.

`LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_SYSTEM`::
    Debug information with system-level scope (set of programs).

`LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_PROGRAM`::
    Debug information with program-level scope (set of processes).

`LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_PROCESS`::
    Debug information with process-level scope (set of modules).

`LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_MODULE`::
    Debug information with module (executable/library) scope (set of units).

`LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_UNIT`::
    Debug information with compilation unit scope (set of functions).

`LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_FUNCTION`::
    Debug information with function-level scope.

`LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_LINE`::
    Debug information with line-level scope (default log level).

`LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG`::
    Debug-level message.