From e729155f3ca3c3fe4888468311c43a06712119d3 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Tue, 9 Jun 2015 16:21:00 +0200 Subject: [PATCH] Add tracelog documentation to lttng-ust(3) Signed-off-by: Mathieu Desnoyers --- doc/man/lttng-ust.3 | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/doc/man/lttng-ust.3 b/doc/man/lttng-ust.3 index 7dae8b53..f57d7f88 100644 --- a/doc/man/lttng-ust.3 +++ b/doc/man/lttng-ust.3 @@ -48,6 +48,40 @@ whereas tracepoint.h is meant for thorough instrumentation of a code base to be integrated with an upstream project. .PP +.SH "USAGE WITH TRACELOG" +.PP +If you want to migrate existing logging (info, errors, ...) +to LTTng UST, you can use the tracelog() interface. +To do it, in a nutshell: + +1) #include + +2) /* in your code, use like a printf, with extra loglevel info. */ + tracelog(info, "Message with integer %d", 1234); + +3) Link your program against liblttng-ust.so. + +4) Enable UST events when tracing with the following sequence of commands + from lttng-tools: + + lttng create + lttng enable-event -u "lttng_ust_tracelog:*" + lttng start + [... run your program ...] + lttng stop + lttng view + +That's it! + +You can replace the enable-event line above with a selection of +loglevels, e.g.: + + lttng enable-event -u -a --loglevel INFO + +Which will gather all events from INFO and more important loglevels. + +.PP + .SH "USAGE WITH TRACEPOINT" .PP The simple way to generate the lttng-ust tracepoint probes is to use the -- 2.34.1