X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=doc%2Fquickstart.txt;h=7078eecc97fb581621b58a250a448ac1f2724c59;hp=ad40385b3b82a2e5c7bd5eaf2c89de09a322f1d0;hb=e3f4dd29a5a67e0e0b3c36baedb71c4f7f23b795;hpb=975fdf538aa48b87f0e22ded95bbbe39a942d2a7 diff --git a/doc/quickstart.txt b/doc/quickstart.txt index ad40385b3..7078eecc9 100644 --- a/doc/quickstart.txt +++ b/doc/quickstart.txt @@ -18,7 +18,7 @@ installed. See http://lttng.org/lttng2.0 for more instructions for that part. For user-space tracing, you'll need an instrumented application, please see http://lttng.org/ust. -lttng-tools provide a session daemon (ltt-sessiond) that acts as a tracing +lttng-tools provide a session daemon (lttng-sessiond) that acts as a tracing registry. To trace any instrumented applications or the kernel, a registered tracing session is needed beforehand. To interact with the session daemon and a tracing session, you should use the lttng command line UI (lttng). @@ -36,7 +36,7 @@ The next sections explain how to do tracing :) Kernel Tracing -------------- -You can start the session daemon by invoking the command "ltt-sessiond", +You can start the session daemon by invoking the command "lttng-sessiond", or let the lttng command line tool do it for you. The session daemon loads the LTTng tracer modules for you if those modules can be found on your system. If they are not found, the kernel tracing feature will be @@ -55,22 +55,30 @@ If you have multiple sessions, you can change the current session by using # lttng set-session myothersession -2) Enable event(s). Here for example, we want only 'sched_switch' and -'sys_enter' events for the kernel (-k/--kernel). +2) Enable all tracepoints and all system call events. -# lttng enable-event sched_switch,sys_enter -k +# lttng enable-event -a -k -or enable ALL events (-a/--all): +3) Enable tracepoint event(s). Here for example, we want only +'sched_switch' and 'sched_wakeup' events for the kernel (-k/--kernel). -# lttng enable-event -a -k +# lttng enable-event sched_switch,sched_wakeup -k + +or enable ALL tracepoint events: + +# lttng enable-event -a -k --tracepoint + +4) Enable all system call event(s). + +# lttng enable-event -a -k --syscall -3) Enable kprobes and/or the function tracer with lttng +5) Enable kprobes and/or the function tracer with lttng This is a new feature made possible by the new LTTng 2.0 kernel tracer. You can enable a dynamic probe and data will be output in the trace along side with your tracing data. -# lttng enable-event aname -k --probe symbol+0xffff7260695 +# lttng enable-event aname -k --probe symbol+0x0 or @@ -83,7 +91,7 @@ Rostedt). Again, data will be output in the trace. # lttng enable-event aname -k --function -4) Enable context information for an event: +6) Enable context information for an event: This is also a new feature which allows you to add context information to an event. For example, you can add the PID along with the event information: @@ -97,7 +105,7 @@ You can on the same line activate multiple context: # lttng add-context -k -e sched_switch -t pid -t nice -t tid -5) Enable perf counter for an event: +7) Enable perf counter for an event: Again, a new powerful feature is the possibility to add perf counter data (using the perf API by Ingo Molnar and Thomas Gleixner) to the trace on a per @@ -107,21 +115,21 @@ event basis. Let say we want to get the CPU cycles at each event: You'll have to use the add-context help for all possible perf counter values. -6) Start tracing: +8) Start tracing: # lttng start Tracing is in progress at this point and traces will be written in $HOME/lttng-traces/mysession--