This is the command lttngtoptrace that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator
PROGRAM:
NAME
lttngtoptrace — Live textual LTTng Trace Viewer
SYNOPSIS
lttngtoptrace [OPTIONS] [EXECUTABLE]
DESCRIPTION
Lttngtoptrace is a live textual LTTng trace viewer, it allows to easily (one command)
start a LTTng session and view the live events. The intent is to do something similar to
strace but less intrusive and more flexible:
- run a command and see it's kernel trace almost instantly without slowing it
down too much (buffered at most 1 second) in combination with the trace of
any other process or the whole system
- follow multiple processes and/or the whole system
- follow the children of all attached processes
- attach to processes by name and/or pid
- actual time taken by the system calls (with reminder of start timestamp)
- sched_switch events to know the context switches that occurred for the
process we are interested in
- current CPU (to see the migrations)
- highlight the trace of a selection of processes while tracing the whole
system to easily see the interactions
- arbitrary kprobe additions to see if a process hits a certain place in the
kernel
Only a subset of the LTTng events are enabled (the statedump, sched_switch,
sched_process_fork and all the system calls).
The events are displayed with additionnal context information than just the raw LTTng
trace (such as the current process name/PID/TID, the start/end time of the current system
call, the delay since the last displayed event (filtering aware)).
OPTIONS
-f Follow threads associated with selected PIDs
-p Comma-separated list of PIDs to display (in addition to the eventual executed
program)
-n Comma-separated list of procnames to display (in addition to the eventual executed
program)
-a In textdump mode, display all events but write in bold the processes we are
interested in (-f and -p)
-k kprobes to insert (same format as lttng enable-event, can be repeated)
-o <filename>
In textdump, output the log in <filename>
EXECUTABLE
Program to run and connect the tracer (can be combined with other options to see
the trace of other processes)
REQUIREMENTS
A working installation of LTTng >= 2.4, the appropriate rights for the user to create a
kernel trace and start daemons (sudo is tried in case the user is not root), Babeltrace =
1.2.4, LTTngTop = 0.3
Use lttngtoptrace online using onworks.net services
