[lttng-dev] [RELEASE] LTTng-UST 2.7.0-rc1

Mathieu Desnoyers mathieu.desnoyers at efficios.com
Wed Jul 15 18:28:51 EDT 2015

LTTng-UST, the Linux Trace Toolkit Next Generation Userspace Tracer, is
port of the low-overhead tracing capabilities of the LTTng kernel tracer
to user-space. The library "liblttng-ust" enables tracing of
applications and libraries.

New and noteworthy:
* tracelog() instrumentation facility. Excerpt from lttng-ust(3):

       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 <lttng/tracelog.h>

       2) /* in your code, use like a printf, with extra loglevel info. */
          tracelog(TRACE_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 com‐
          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 TRACE_INFO

       Which  will  gather  all  events  from  TRACE_INFO  and  more important

* File-backed UST: allow mapping ring buffer into filesystems. Useful
  in combination with pramfs or DAX+pmem (kernels 4.1+ for DAX and
  4.2+ for pmem) to keep tracer ring buffers around in persistent
  memory upon system reboot.

* getcpu and clock plugin support. Allows user to provide their own
  getcpu and clock source implementation as shared objects.

2015-07-15 (Pet Fire Safety Day) lttng-ust 2.7.0-rc1
        * Fix: Use $enableval with AC_ARG_ENABLE
        * Fix: Cleanup local_apps sock_info in lttng_ust_cleanup
        * Fix: handle sys_futex EINTR and EWOULDBLOCK
        * Fix: update liburcu URL
        * .gitignore: ignore Python agent generated files
        * Add ctf_sequence_hex() macro
        * Fix: set soinfo_data's vdso flag correctly in base address statedump
        * Fix: running java examples out of tree
        * Fix: java class check when uudecode is not present
        * Cleanup: remove extra whitespace in configure output
        * Default to no unaligned access on unsupported archs
        * cleanup: Coding style fixes to the Java agent
        * cleanup: Mark obsolete JUL agent as @Deprecated
        * Fix compilation warnings in the Java agent
        * Fix: out of tree build of java agents
        * Fix: Use env CLASSPATH when building log4j example
        * Fix: build log4j example when enabled
        * Bump tracer version to 2.7.0-pre
        * Fix: perform volatile load of tracepoint state
        * Add demo-tracelog to gitignore file
        * Add aarch64 support to configure
        * Implement cpu_id context for filtering
        * ust cyg-profile: use same class for entry and exit
        * Fix: function instrumentation ip context
        * Fix: liblttng-ust-dl ip context
        * Remove caller field from malloc events
        * Fix: pthread wrapper ip context
        * Fix: lttng-ust-malloc ip context
        * Allow TP_IP_PARAM arg name to be configured
        * tracelog: use same class for all loglevels
        * fix tracelog namespacing of loglevels
        * Add tracelog documentation to lttng-ust(3)
        * Implement demo-tracelog example
        * Implement tracelog API
        * Fix: fetch caller address from tracef()
        * Rename helper providers and events for consistency
        * Refactor state dump system
        * Refactor Python agent
        * Fix: building probe providers with C++ compiler
        * Fix: use lttng_secure_getenv to handle env. vars. involving paths
        * Fix: Don't wait during registration if clock_gettime() fails
        * Fix: getcpu/clock plugin handle leak
        * Fix: add missing new ldl dependency for liblttng-ust-ctl
        * Fix: add missing getenv wrapper
        * Fix: add missing lttng-clock.c
        * Fix: add missing ust-clock.h
        * clock plugin example: use shift and mul
        * Implement getcpu override
        * Implement clock override plugin support
        * Add tracepoint_enabled() macro
        * Move file creation/unlink from liblttng-ust-ctl to consumerd
        * Implement file-backed ring buffer
        * Fix: oot build: missing top_builddir include
        * Fix: Mismatching code and console output in log4j example
        * Update manpage about LTTNG_UST_DEBUG effect
        * Don't output to stderr from lib unless DEBUG is activated
        * Remove usterr.h, use usterr-signal-safe.h everywhere instead
        * Fix: out-of-tree build: wrong file path for sed input
        * Fix: make dist: python agent file handling
        * Fix: java-agent: out-of-tree path to java manifest
        * Add return address to liblttng-ust-libc-wrapper
        * Fix: missing parenthesis in offset_align_floor
        * Fix: add ustctl_has_perf_counters
        * Fix: add urcu-bp TLS fixup
        * Fix: add missing poll.h include
        * Fix: get_subbuf: bound number of consumerd retry
        * Fix: man: you can't link a lib with a static lib
        * Fix: context alignment not properly handled
        * Fix: Shorthand option -cp not supported in all version of Java
        * Fix: allow tracepoints to build with --std=c99
        * Bump UST ABI for new release cycle
        * Cleanup: remove "disabled" flag for new release cycle
        * Fix: filter attach vs event enable race
        * Fix: add a configure check for weak symbols support
        * Fix coverity warning about sizeof(void **) != sizeof(void *)
        * Fix: off-by-one in sequence filter comparator
        * Fix: Java Agent JAR file symlink should be created after objects install
        * Fix: Add versioning to liblttng-ust-agent JAR
        * Fix: Warn when log4j version is too old
        * Update Java agent documentation
        * Fix: Try loading classes using the thread context class loader
        * Add Python agent support
        * Update version name

Project website: http://lttng.org
Documentation: http://lttng.org/docs
Download link: http://lttng.org/download

Mathieu Desnoyers
EfficiOS Inc.

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