Bug #619: lttng enable-channel no longer works as before - LTTng-tools - LTTng bugs repository

Actions

Copy link

Bug #619

closed

lttng enable-channel no longer works as before

Added by Daniel U. Thibault over 11 years ago. Updated over 11 years ago.

Status:

Resolved

Priority:

Normal

Assignee:

Target version:

LTTng - 2.3

Start date:

08/13/2013

Due date:

% Done:

100%

Estimated time:

Description

It used to be you could turn channels on and off during a trace, but that is no longer true:

$ lttng create toy
Session toy created.
Traces will be written in /home/daniel/lttng-traces/toy-20130813-163606
$ lttng enable-channel -k ch1
Kernel channel ch1 enabled for session toy
$ lttng start
Tracing started for session toy
$ lttng disable-channel -k ch1
Kernel channel ch1 disabled for session toy
$ lttng enable-channel -k ch1
Error: Channel ch1: Tracing already started (session toy)
Warning: Some command(s) went wrong
$ lttng stop
Waiting for data availability
Tracing stopped for session toy
$ lttng enable-channel -k ch1
Error: Channel ch1: Tracing already started (session toy)
Warning: Some command(s) went wrong

Once the session is started, you can disable channels but you cannot re-enable them. Even if the trace is paused.