From 617d7d159c22a17dd0191597945eb00303935e96 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Fri, 22 Jul 2011 15:04:30 -0400 Subject: [PATCH 1/1] Update quickstart for new perf UI Signed-off-by: Mathieu Desnoyers --- doc/quickstart.txt | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/doc/quickstart.txt b/doc/quickstart.txt index abf61e76c..0cf44d69b 100644 --- a/doc/quickstart.txt +++ b/doc/quickstart.txt @@ -23,13 +23,13 @@ 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). -Here is a list of some new powerful features the LTTng 2.0 kernel tracer -offers: +Here is a list of some powerful features the LTTng 2.0 kernel tracer offers: * Kprobes support * Function Tracer support * Context information support (add context data to an event) * Perf counter support + * Tracepoint support The next sections explain how to do tracing :) @@ -67,18 +67,18 @@ or enable ALL events (-a/--all): 3) 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 Kprobe (by Masami Hiramatsu) and data will be output in the trace -along side with your tracing data. +enable a dynamic probe and data will be output in the trace along side with +your tracing data. -# lttng enable-event aname --kprobe symbol+0xffff7260695 +# lttng enable-event aname --probe symbol+0xffff7260695 or -# lttng enable-event aname --kprobe 0xffff7260695 +# lttng enable-event aname --probe 0xffff7260695 -Either an
or a can be used for kprobes. +Either an
or a can be used for probes. -You can also enable function tracer, which uses the ftrace API (by Steven +You can also enable function tracer, which uses the Ftrace API (by Steven Rostedt). Again, data will be output in the trace. # lttng enable-event aname --function @@ -88,22 +88,22 @@ Rostedt). Again, data will be output in the trace. 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: -# lttng add-context -k -e sched_switch -t 0 +# lttng add-context -k -e sched_switch -t pid At this point, you will have to look at 'lttng add-context --help' for all possible context type which are integer values. You can on the same line activate multiple context: -# lttng add-context -k -e sched_switch -t 0 -t 2 -t 4 +# lttng add-context -k -e sched_switch -t pid -t nice -t tid 5) 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 -event basis. Let say we want to get the CPU cycles at each define event: +event basis. Let say we want to get the CPU cycles at each event: -# lttng add-context -k -e sched_switch -t perf --perf-type hw --perf-id cpu_cycles +# lttng add-context -k -e sched_switch -t perf:cpu-cycles You'll have to use the add-context help for all possible perf counter values. -- 2.34.1