LTTng-UST, the Linux Trace Toolkit Next Generation Userspace Tracer,
is a low-overhead application tracer. The library "liblttng-ust" enables
tracing of applications and libraries.
* New and noteworthy in these releases:
Specific to 2.13.7, a fix for misaligned urcu reader accesses was
introduced. It only applies to the lttng-ust 2.13 branch because
it implements its own "lttng-ust-urcu" flavor.
Also specific to 2.13.7, "sync" vs "unsync" enablers are introduced
to eliminate an O(n*m) algorithm:
Eliminate iteration over unmodified enablers when synchronizing the
enablers vs event state.
The intent is to turn a O(m*n) algorithm (m = number of enablers, n =
number of event probes) into a O(n) when enabling many additional events
when tracing is active.
Specifically in 2.12.9, the rfork() wrapper is fixed: it was not
passing the flags arguments. This was fixed in a larger commit
in the master and stable-2.13 branches.
Both stable branches include:
- a build system fix for documentation examples with old autoconf when
used with a relative path.
- a clang warning fix around volatile qualifier on function pointers.
- Python agent uplift to adapt to modern python (>= 3.10),
- a possible race condition in the ustfork helper.
Enjoy!
Mathieu
Project website: https://lttng.org
Documentation: https://lttng.org/docs
Download link: https://lttng.org/download
Detailed change logs:
2024-01-10 (National Houseplant Appreciation Day) lttng-ust 2.13.7
* fix: invoke MKDIR_P before changing directories
* fix: -Wsingle-bit-bitfield-constant-conversion with clang16
* fix: clean java inner class files in examples
* Introduce sync vs unsync enablers
* Fix: misaligned urcu reader accesses
* ustfork: Fix warning about volatile qualifier
* ustfork: Fix possible race conditions
* Fix: tracepoint: Remove trailing \ at the end of macro
* fix: python agent: use stdlib distutils when setuptools is installed
* fix: python agent: install on Debian python >= 3.10
* fix: python agent: Add a dependency on generated files
* python: use setuptools with python >= 3.12
2024-01-10 (National Houseplant Appreciation Day) lttng-ust 2.12.9
* fix: invoke MKDIR_P before changing directories
* fix: clean java inner class files in examples
* ustfork: Fix warning about volatile qualifier
* ustfork: Fix possible race conditions
* Fix: FreeBSD: Pass flags arguments to rfork wrapper
* fix: python agent: use stdlib distutils when setuptools is installed
* fix: python agent: install on Debian python >= 3.10
* fix: python agent: Add a dependency on generated files
* python: use setuptools with python >= 3.12
--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com