LTTng development roadmap, snapshot 20110116

Hi,

I just released a development snapshot of the current LTTng so those interested can start building it in various configurations. The targets of this development phase were as follows:

1) The size of the kernel patchset has been shrinked for Linux distributions by removing all LTTng-specific instrumentation from the tree.

2) The lttng-modules package now implements an ABI based on anonymous file descriptors (inspired from perf) rather than the full-blown VFS tree the previous LTTng versions were implementing.

3) lttng-modules now exports trace data and metadata in the CTF (Common Trace Format).

4) lttng-modules now uses the Generic Ring Buffer Library.

The kernel tree snapshot is available as a tarball at:
http://lttng.org/files/lttng/patch-2.6.37-lttng-dev-snapshot-20110116.tar.bz2

The kernel patchset contains the following subdirectories:

trace-event-merged/ (3 patches, merged in the tracing tree)

 5 files changed, 22 insertions(+), 17 deletions(-)

trace-event-semicolon-removal/ (29 patches)

 37 files changed, 730 insertions(+), 662 deletions(-)

trace-event-assign-macros/ (8 patches)

 10 files changed, 251 insertions(+), 223 deletions(-)

trace-clock/ (19 patches)

 60 files changed, 2750 insertions(+), 216 deletions(-)

lib-ring-buffer/ (9 patches)

 34 files changed, 6635 insertions(+), 71 deletions(-)

lttng/ (3 patches)

 3 files changed, 11 insertions(+), 1 deletion(-)

lib-ring-buffer-improvements/ (7 patches)

 12 files changed, 279 insertions(+), 14 deletions(-)

The LTTng kernel patchset is needed to build the current lttng-modules git tree (a kernel module package). To fetch it:

git clone git://git.lttng.org/lttng-modules.git
(.c and .h files: 3170 lines total)

I currently have only a rather basic test program to interface with the new ABI (available at http://lttng.org/files/lttng/test-lttng-ioctl.c), but I am planning to work on the new strace-like command line program within the next weeks (note: the location of the debugfs LTTng file will very likely change). The objective is to create one single command-line tool to control both the LTTng kernel tracer and the UST user-space tracer.

Thanks,

Mathieu

Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com