X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=README;h=1d731ab76c4d8d8ab1fe787f12d51d4adda7bc8a;hb=refs%2Fheads%2Fstable-2.5;hp=77b670b8ac7b90797aad6174611fd9812ff47d4c;hpb=3c97f6b5109d34568a2458b39c9a6c525e34664d;p=lttng-ust.git diff --git a/README b/README index 77b670b8..1d731ab7 100644 --- a/README +++ b/README @@ -1,83 +1,191 @@ -LTTNG USERSPACE TRACER (UST) +LTTNG USERSPACE TRACER (LTTng-UST) ---------------------------- -For the UST manual, see: http://lttng.org/files/ust/manual/ust.html +UST web site: http://lttng.org Updated versions of this package may be found at: - * Releases: http://lttng.org/files/ust/releases - * GitWeb: http://git.dorsal.polymtl.ca (project: ust) - * Git: git://git.dorsal.polymtl.ca/git/ust.git - + * Releases: http://lttng.org/download + * GitWeb: http://git.lttng.org (project: lttng-ust) + * Git: git://git.lttng.org/lttng-ust.git PREREQUISITES: - liburcu - Userspace RCU library, by Mathieu Desnoyers and Paul E. McKenney - * Releases: http://lttng.org/files/ust/releases - * GitWeb: http://lttng.org/cgi-bin/gitweb.cgi?p=userspace-rcu.git;a=summary - * Git: git://lttng.org/userspace-rcu.git - -> This release was tested with liburcu v0.4.1 + -> This release depends on liburcu v0.7.2 + * Debian/Ubuntu package: liburcu-dev + * Website: http://lttng.org/urcu + * Releases: http://lttng.org/files/urcu + * GitWeb: http://lttng.org/cgi-bin/gitweb.cgi?p=userspace-rcu.git;a=summary + * Git: git://git.urcu.so/userspace-rcu.git - - libkcompat +For developers using the git tree: - Linux kernel userspace compatibility library. - (Provides userspace ports of some kernel APIs.) - * Releases: http://lttng.org/files/ust/releases - * GitWeb: http://git.dorsal.polymtl.ca (project: libkcompat) - * Git: git://git.dorsal.polymtl.ca/git/libkcompat.git +This source tree is based on the autotools suite from GNU to simplify +portability. Here are some things you should have on your system in order to +compile the git repository tree : - -> This release was tested with libkcompat v0.1 +- GNU autotools (automake >=1.10, autoconf >=2.50, autoheader >=2.50) + (make sure your system wide "automake" points to a recent version!) +- GNU Libtool >=2.2 + (for more information, go to http://www.gnu.org/software/autoconf/) +- Perl (optional) + Needed for make check and tests. +If you get the tree from the repository, you will need to use the "bootstrap" +script in the root of the tree. It calls all the GNU tools needed to prepare the +tree configuration. INSTALLATION INSTRUCTIONS: - - Download, compile and install liburcu and libkcompat. + - Download, compile and install liburcu. - In this package's tree, run ./configure. - Run make. - Run make install. - Run ldconfig. - - See the manual for usage instructions. + If compiling from the git repository, run ./bootstrap before running + the configure script, to generate it. + + Note that configure sets '/usr/local' as the default prefix for files it + installs. However, this path is not part of most distributions' default + library path which will cause builds depending on liblttng-ust to fail unless + '-L/usr/local/lib' is added to LDFLAGS. You may provide a custom prefix to + configure by using the --prefix switch. Note that LTTng-UST needs to + be a shared library, even if the tracepoint probe provider is statically + linked into the application. + +USAGE: + + - Create an instrumentation header following the tracepoint examples. + See lttng/tracepoint.h, and examples. + + There are 2 ways to compile the Tracepoint Provider with the + application: either statically or dynamically. Please follow + carefully: + + 1.1) Compile the Tracepoint provider with the application, either + directly or through a static library (.a): + - Into exactly one object of your application: define + "TRACEPOINT_DEFINE" and include the tracepoint provider. + - Use "-I." for the compilation unit containing the tracepoint + provider include (e.g. tp.c). + - Link application with "-ldl" on Linux, with "-lc" on BSD. + - If building the provider directly into the application, + link the application with "-llttng-ust". + - If building a static library for the provider, link the static + library with "-llttng-ust". + - Include the tracepoint provider header into all C files using + the provider. + - Examples: + - doc/examples/easy-ust/ sample.c sample_component_provider.h + tp.c Makefile + - doc/examples/hello-static-lib/ hello.c tp.c ust_test_hello.h + Makefile + + 2) Compile the Tracepoint Provider separately from the application, + using dynamic linking: + - Into exactly one object of your application: define + "TRACEPOINT_DEFINE" _and_ also define + "TRACEPOINT_PROBE_DYNAMIC_LINKAGE", then include the tracepoint + provider header. + - Include the tracepoint provider header into all instrumented C + files that use the provider. + - Compile the tracepoint provider with "-I.". + - Link the tracepoint provider with "-llttng-ust". + - Link application with "-ldl" on Linux, "-lc" on BSD. + - Set a LD_PRELOAD environment to preload the tracepoint provider + shared object before starting the application when tracing is + needed. Another way is to dlopen the tracepoint probe when needed + by the application. + - Example: + - doc/examples/demo demo.c tp*.c ust_tests_demo*.h demo-trace Makefile + + - Note about dlclose() usage: it is not safe to use dlclose on a + provider shared object that is being actively used for tracing due + to a lack of reference counting from lttng-ust to the used shared + object. + - Enable instrumentation and control tracing with the "lttng" command + from lttng-tools. See lttng-tools doc/quickstart.txt. + - Note for C++ support: since LTTng-UST 2.3, both tracepoints and + tracepoint probes can be compiled in C++. To compile tracepoint probes + in C++, you need g++ >= 4.7 or Clang. + + +ENVIRONMENT VARIABLES: + + - liblttng-ust debug can be activated by setting the environment variable + "LTTNG_UST_DEBUG" when launching the application. It can also be enabled + at compile-time by compiling libust with -DLTTNG_UST_DEBUG. + + - The environment variable "LTTNG_UST_REGISTER_TIMEOUT" can be used to + specify how long the applications should wait for sessiond + "registration done" command before proceeding to execute the main + program. The default is 3000ms (3 seconds). The timeout value is + specified in milliseconds. The value 0 means "don't wait". The value + -1 means "wait forever". Setting this environment variable to 0 is + 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: - LTTV is used for viewing UST traces. LTTV may be obtained at - http://lttng.org in the Downloads section. + Use babeltrace for viewing traces generated by LTTng UST 2.x. + See http://lttng.org for download. + + +CONTACT: + Maintainer: Mathieu Desnoyers + Mailing list: lttng-dev@lists.lttng.org PACKAGE CONTENTS: This package contains the following elements. - - libust + - liblttng-ust The actual userspace tracing library that must be linked to the instrumented programs. - - ustctl - A program to control the tracing of userspace applications. It can list - markers, start the tracing, stop the tracing, enable/disable markers, etc. + - include + The public header files that will be installed on the system. - - ustd - The daemon that collects trace data and writes it to the disk. + - tests + Various test programs - - doc - The documentation. + - liblttng-ust-libc-wrapper + An example library that can be LD_PRELOAD'ed to instrument some + calls to libc (currently malloc() and free()) in any program without + need to recompile it. - - hello - An example application that uses the userspace tracer. + - liblttng-ust-fork + A library that is LD_PRELOAD'ed, and that hijacks calls to several system + calls in order to trace across these calls. It _has_ to be LD_PRELOAD'ed + in order to hijack calls. In contrast, libust may be linked at build time. - - libmallocwrap - An example library that can be LD_PRELOAD'ed to instrument calls to malloc() - in any program without need to recompile it. + - liblttng-ust-ctl + A library to control tracing in other processes. Used by lttng-tools. - - libinterfork - A library that is LD_PRELOAD'ed, and that hijacks calls to several system - calls in order to trace across these calls. + - liblttng-ust-comm + A static library shared between libust and lttng-tools, that + provides functions that allow these components to communicate together. + + - libringbuffer + The ring buffer implementation used within LTTng-UST. + + - snprintf + An asynchronous signal-safe version of snprintf. + + - liblttng-ust-java + A simple library that uses JNI to allow tracing in java programs. + See liblttng-ust-java/README for build instructions.