On Wed, Mar 31, 2021 at 12:55:53PM -0500, Ramesh Errabolu wrote: > root@RocrLnx23:~/git/compute/out/ubuntu-18.04/18.04/bin# ls ~/ | grep -i ltt > root@RocrLnx23:~/git/compute/out/ubuntu-18.04/18.04/bin# lttng create > my-kernel-session --output=~/my-kernel-trace > Session my-kernel-session created. > Traces will be output to > /home/user1/git/compute/out/ubuntu-18.04/18.04/bin/~/my-kernel-trace > root@RocrLnx23:~/git/compute/out/ubuntu-18.04/18.04/bin# *lttng list > --kerne*l > *Error: Unable to list kernel events: Kernel tracer not available*
Well this would be the first thing to look at. First let's deactivate the lttng-sessiond.service installed by the packages. systemctl stop lttng-sessiond.service You might want to reanable it later. > > root@RocrLnx23:~/git/compute/out/ubuntu-18.04/18.04/bin# ps -ef | grep ltt > root 1002 1 0 12:16 ? 00:00:00 /usr/bin/lttng-sessiond > root 1054 1002 0 12:16 ? 00:00:00 */usr/bin/lttng-sessiond* > root 3145 2861 0 12:51 pts/0 00:00:00 grep --color=auto ltt > root@RocrLnx23:~/git/compute/out/ubuntu-18.04/18.04/bin# Make sure after the systemctl call that no lttng-sessiond process is running. Now let's launch a lttng-sessiond by hand with a bit more verbosity. For now let's stick to the root user. # lttng-sessiond -vvv --verbose-consumer -b > /tmp/lttng-sessiond.log 2>&1 # pkill lttng-sessiond Please share the content of /tmp/lttng-sessiond.log using a pasting service (paste.ubuntu.com). Also please provide the output of: # uname -a # find /lib/modules/$(uname -r)/ | grep lttng # dmesg | grep lttng But again, the cyg-profile helper library is meant for Userspace tracing. With the app running and having the LD_PRELOAD correctly set, and a sessiond running. # lttng list -u If there is nothing, well you can start the application with the following and share the output of it (make sure to remove any output from your application if sensitive data is present) # LD_PRELOAD=.... LTTNG_UST_DEBUG=1 your_application_here Note that debug log will be outputted on stderr. Cheers -- Jonathan Rajotte-Julien EfficiOS _______________________________________________ lttng-dev mailing list lttng-dev@lists.lttng.org https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev