X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=README;h=78160a30f8210e0cdb9e8e6e8483aa3a6204e117;hb=refs%2Fheads%2Fcygwin-2.0-experimental;hp=e2b52aa026f74a3ff598c774bc034baefe01c5aa;hpb=476037d9a24fdd5e339e3565743aadb9cb8a0a96;p=lttng-ust.git diff --git a/README b/README index e2b52aa0..78160a30 100644 --- a/README +++ b/README @@ -90,15 +90,11 @@ USAGE: - Link application with "-ldl". - Set a LD_PRELOAD environment to preload the tracepoint provider shared object before starting the application when tracing is - needed. + needed. Another way is to dlopen the tracepoint probe when needed + by the application. - Example: - tests/demo/ demo.c tp*.c ust_tests_demo*.h demo-trace - - Note about dlopen() usage: due to locking side-effects due to the - way libc lazily resolves Thread-Local Storage (TLS) symbols when a - library is dlopen'd, linking the tracepoint probe or liblttng-ust - with dlopen() is discouraged. They should be linked with the - application using "-llibname" or loaded with LD_PRELOAD. - Enable instrumentation and control tracing with the "lttng" command from lttng-tools. See lttng-tools doc/quickstart.txt. @@ -117,6 +113,10 @@ ENVIRONMENT VARIABLES: recommended for applications with time constraints on the process startup time. + - The compilation flag "-DLTTNG_UST_DEBUG_VALGRIND" should be enabled + at build time to allow liblttng-ust to be used with valgrind + (side-effect: disables per-cpu buffering). + TRACE VIEWER: