[lttng-modules.git] / README

LTTng 2.0 modules

Mathieu Desnoyers
July 19, 2011

LTTng 2.0 kernel modules build against a vanilla or distribution kernel, without
need for additional patches. Other features:

- Produces CTF (Common Trace Format) natively,
  (http://www.efficios.com/ctf)
- Tracepoints, Function tracer, CPU Performance Monitoring Unit (PMU)
  counters and kprobes support,
- Integrated interface for both kernel and userspace tracing,
- Have the ability to attach "context" information to events in the
  trace (e.g. any PMU counter, pid, ppid, tid, comm name, etc).
  All the extra information fields to be collected with events are
  optional, specified on a per-tracing-session basis (except for
  timestamp and event id, which are mandatory).

To build and install, you will need to have your kernel headers available (or
access to your full kernel source tree), and use:

make
make modules_install

If you need to specify the target directory to the kernel you want to build
against, use:

KERNELDIR=path_to_kernel_dir make
KERNELDIR=path_to_kernel_dir make modules_install

Use lttng-tools (git://git.lttng.org/lttng-tools.git) to control the tracer.
LTTng tools should automatically load the kernel modules when needed.

Use Babeltrace (git://git.efficios.com/babeltrace.git) to print traces as a
human-readable text log.

Please note that the LTTng-UST 2.0 (user-space tracing counterpart of LTTng 2.0)
is still in active development and not released yet.

So far, it has been tested on vanilla kernels 2.6.38 and 2.6.39 (on x86 at the
moment). It should work fine with newer kernels and other architectures, but
expect build issues with kernels older than 2.6.36. The clock source currently
used is the standard gettimeofday (slower, less scalable and less precise than
the LTTng 0.x clocks). Support for LTTng 0.x clocks will be added back soon into
LTTng 2.0.
Commit	Line	Data
98541fcf MD	1	LTTng 2.0 modules
	2
	3	Mathieu Desnoyers
	4	July 19, 2011
	5
	6	LTTng 2.0 kernel modules build against a vanilla or distribution kernel, without
	7	need for additional patches. Other features:
	8
	9	- Produces CTF (Common Trace Format) natively,
	10	(http://www.efficios.com/ctf)
fe178379 MD	11	- Tracepoints, Function tracer, CPU Performance Monitoring Unit (PMU)
fe178379 MD	12	counters and kprobes support,
98541fcf MD	13	- Integrated interface for both kernel and userspace tracing,
98541fcf MD	14	- Have the ability to attach "context" information to events in the
fe178379 MD	15	trace (e.g. any PMU counter, pid, ppid, tid, comm name, etc).
	16	All the extra information fields to be collected with events are
	17	optional, specified on a per-tracing-session basis (except for
	18	timestamp and event id, which are mandatory).
98541fcf MD	19
	20	To build and install, you will need to have your kernel headers available (or
	21	access to your full kernel source tree), and use:
	22
	23	make
9d4c2d78	24	make modules_install
98541fcf MD	25
	26	If you need to specify the target directory to the kernel you want to build
	27	against, use:
	28
	29	KERNELDIR=path_to_kernel_dir make
9d4c2d78	30	KERNELDIR=path_to_kernel_dir make modules_install
98541fcf	31
bd2fc8af MD	32	Use lttng-tools (git://git.lttng.org/lttng-tools.git) to control the tracer.
	33	LTTng tools should automatically load the kernel modules when needed.
	34
	35	Use Babeltrace (git://git.efficios.com/babeltrace.git) to print traces as a
	36	human-readable text log.
	37
	38	Please note that the LTTng-UST 2.0 (user-space tracing counterpart of LTTng 2.0)
	39	is still in active development and not released yet.
98541fcf MD	40
	41	So far, it has been tested on vanilla kernels 2.6.38 and 2.6.39 (on x86 at the
	42	moment). It should work fine with newer kernels and other architectures, but
	43	expect build issues with kernels older than 2.6.36. The clock source currently
	44	used is the standard gettimeofday (slower, less scalable and less precise than
	45	the LTTng 0.x clocks). Support for LTTng 0.x clocks will be added back soon into
	46	LTTng 2.0.