-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/lttng2.0
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
-
+ * Website: http://lttng.org/lttng2.0
+ * Releases: http://lttng.org/files/lttng-ust
+ * 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 v0.3.4
+ -> This release depends on liburcu v0.6.6
+ * 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://lttng.org/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/)
+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 in the doc/ directory for usage instructions.
+ If compiling from the git repository, run ./bootstrap before running
+ the configure script, to generate it.
+
+
+USAGE:
+
+ - Create an instrumentation header following the tracepoint examples.
+ See lttng/tracepoint.h, and examples.
+ - Either compile the Tracepoint probes with the application:
+ - Use "-I." for the compilation unit containing the tracepoint
+ provider include (e.g. tp.c).
+ - Link application with "-ldl -llttng-ust".
+ - Example:
+ tests/hello/ hello.c tp.c ust_tests_hello.h Makefile.example
+ - Or compile the Tracepoint probes separately from the application,
+ using dynamic linking:
+ - Compile the tracepoint provider with "-I.".
+ - Link the tracepoint provider with "-llttng-ust".
+ - Link application with "-ldl".
+ - Set a LD_PRELOAD environment to preload the tracepoint provider
+ shared object before starting the application when tracing is
+ needed.
+ - 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.
+
+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.
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 2.0.
+ See http://lttng.org for download.
+
+CONTACT:
+
+ Maintainer: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ 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
+ 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.