From mboxrd@z Thu Jan 1 00:00:00 1970 From: tom.deneau@amd.com (Deneau, Tom) Date: Wed, 31 May 2017 23:18:07 +0000 Subject: [lttng-dev] Error: Kernel create channel failed In-Reply-To: <20170531183000.vh5y266by4hmtmb3@psrcode-TP-X230> References: <20170531183000.vh5y266by4hmtmb3@psrcode-TP-X230> Message-ID: Thanks, the new packages installed fine. My original problem I solved by killing lttng-sessiond and restarting it... -- Tom -----Original Message----- From: Jonathan Rajotte-Julien [mailto:jonathan.rajotte-julien@efficios.com] Sent: Wednesday, May 31, 2017 1:30 PM To: Deneau, Tom Cc: lttng-dev at lists.lttng.org Subject: Re: [lttng-dev] Error: Kernel create channel failed Hi, On Tue, May 30, 2017 at 02:15:47PM +0000, Deneau, Tom wrote: > I seem to have gotten my lttng into a state where kernel tracing does not work. > I have tried uninstalling and reinstalling packages with no luck and also building from source. > Any suggestions welcome. > > My distro is Ubuntu 16.04 but the kernel is 4.10.0-20-generic. Are you using the hwe package? (linux-generic-hwe-16.04-edge) > > I have installed 2.9 using > apt install linux-tools-generic dkmso If using the hwe package you probably want to use the equivalent linux-tool-generic hwe package. > apt-add-repository ppa:lttng/stable-2.9 apt-get update apt install -y > lttng-tools liblttng-ust-dev liblttng-ust-agent-java > python3-lttngust lttng-modules-dkms wget > http://ftp.us.debian.org/debian/pool/main/l/lttng-modules/lttng-module > s-dkms_2.9.1-1_all.deb dpkg -i lttng-modules-dkms_2.9.1-1_all.deb I guess that this was to "fix" the installation error you had with installing lttng-modules-dkms. Reporting the installation issue would have been more straightforward. The ppa packages were updated yesterday to fix the issue on installation. Please update (apt update/upgrade) all lttng related packages. Also make sure to install babeltrace (apt install babeltrace) with updated libbabeltrace* dependencies. > apt install -y babeltrace python3-babeltrace > > After lttng create test, I then try > > # lttng -vvv enable-channel k -k --num-subbuf 64 --subbuf-size 512k > DEBUG1 - 08:27:54.415995 [13972/13972]: Channel subbuf num set to 64 > (in cmd_enable_channels() at commands/enable_channels.c:420) > DEBUG1 - 08:27:54.416045 [13972/13972]: Channel subbuf size set to > 524288 (in cmd_enable_channels() at commands/enable_channels.c:384) > DEBUG2 - 08:27:54.416080 [13972/13972]: Config file path found: /root > (in _get_session_name() at utils.c:63) > DEBUG1 - 08:27:54.416087 [13972/13972]: Session name found: test (in > _get_session_name() at utils.c:64) > DEBUG1 - 08:27:54.416099 [13972/13972]: Enabling channel k (in > enable_channel() at commands/enable_channels.c:225) > DEBUG1 - 08:27:54.416129 [13972/13972]: LSM cmd type : 5 (in > send_session_msg() at lttng-ctl.c:135) > Error: Channel k: Kernel create channel failed (session test) > Error: Command error > DEBUG1 - 08:27:54.416479 [13972/13972]: Clean exit (in clean_exit() at > lttng.c:149) I tested ppa stable 2.9 installation on both vanilla 16.04 and 16.04 with the 4.10.0-21-generic kernel provided by linux-generic-hwe-16.04-edge. Both works with the updated ppa (update performed by Michael Jeanson). Only had a minor dependency issue with babeltrace but it was fixed by reinstalling it. Cheers > > > _______________________________________________ > lttng-dev mailing list > lttng-dev at lists.lttng.org > https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev -- Jonathan Rajotte-Julien EfficiOS