Bug #571: lttng-tools 2.2.0-rc2: kernel enable-channel for a suspended trace fails arbitrarily - LTTng-tools - LTTng bugs repository

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Bug #571

closed

lttng-tools 2.2.0-rc2: kernel enable-channel for a suspended trace fails arbitrarily

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

Status:

Resolved

Priority:

Normal

Assignee:

David Goulet

Target version:

LTTng - 2.2

Start date:

06/25/2013

Due date:

% Done:

100%

Estimated time:

Description

$ sudo -H lttng create sss
$ sudo -H lttng enable-channel k0 -k
Kernel channel k0 enabled for session sss
$ sudo -H lttng enable-channel k1 -k --subbuf-size 4096
Kernel channel k1 enabled for session sss
$ sudo -H lttng start
Tracing started for session sss
$ sudo -H lttng stop
Waiting for data availability
Tracing stopped for session sss
$ sudo -H lttng enable-channel k2 -k --subbuf-size 4096
PERROR [20531/20631]: ioctl kernel create channel: Invalid argument (in kernel_create_channel() at kernel.c:144)
Error: Channel k2: Kernel create channel failed (session sss)
Warning: Some command(s) went wrong
$ sudo -H lttng enable-channel k2 -k
PERROR [20531/20631]: ioctl kernel create channel: Invalid argument (in kernel_create_channel() at kernel.c:144)
Error: Channel k2: Kernel create channel failed (session sss)
Warning: Some command(s) went wrong

This inability to enable new channels (for a suspended trace) seems to affect only the kernel domain (in the user-space domain, new channels may be enabled at any time, even while the trace is running). If this is a feature, it ought to be mentioned in the man pages.