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authorLinus Torvalds <torvalds@linux-foundation.org>2009-06-10 19:53:40 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-10 19:53:40 -0700
commit862366118026a358882eefc70238dbcc3db37aac (patch)
tree4eb62bc10327a5afac064a95a091ea05ecd2acc1 /Documentation
parent57eee9ae7bbcfb692dc96c739a5184adb6349733 (diff)
parent511b01bdf64ad8a38414096eab283c7784aebfc4 (diff)
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Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (244 commits) Revert "x86, bts: reenable ptrace branch trace support" tracing: do not translate event helper macros in print format ftrace/documentation: fix typo in function grapher name tracing/events: convert block trace points to TRACE_EVENT(), fix !CONFIG_BLOCK tracing: add protection around module events unload tracing: add trace_seq_vprint interface tracing: fix the block trace points print size tracing/events: convert block trace points to TRACE_EVENT() ring-buffer: fix ret in rb_add_time_stamp ring-buffer: pass in lockdep class key for reader_lock tracing: add annotation to what type of stack trace is recorded tracing: fix multiple use of __print_flags and __print_symbolic tracing/events: fix output format of user stack tracing/events: fix output format of kernel stack tracing/trace_stack: fix the number of entries in the header ring-buffer: discard timestamps that are at the start of the buffer ring-buffer: try to discard unneeded timestamps ring-buffer: fix bug in ring_buffer_discard_commit ftrace: do not profile functions when disabled tracing: make trace pipe recognize latency format flag ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/DocBook/Makefile3
-rw-r--r--Documentation/DocBook/tracepoint.tmpl89
-rw-r--r--Documentation/kernel-parameters.txt27
-rw-r--r--Documentation/trace/events.txt90
-rw-r--r--Documentation/trace/ftrace.txt2
-rw-r--r--Documentation/trace/power.txt17
6 files changed, 214 insertions, 14 deletions
diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile
index b1eb661e6302..9632444f6c62 100644
--- a/Documentation/DocBook/Makefile
+++ b/Documentation/DocBook/Makefile
@@ -13,7 +13,8 @@ DOCBOOKS := z8530book.xml mcabook.xml device-drivers.xml \
gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml \
genericirq.xml s390-drivers.xml uio-howto.xml scsi.xml \
mac80211.xml debugobjects.xml sh.xml regulator.xml \
- alsa-driver-api.xml writing-an-alsa-driver.xml
+ alsa-driver-api.xml writing-an-alsa-driver.xml \
+ tracepoint.xml
###
# The build process is as follows (targets):
diff --git a/Documentation/DocBook/tracepoint.tmpl b/Documentation/DocBook/tracepoint.tmpl
new file mode 100644
index 000000000000..b0756d0fd579
--- /dev/null
+++ b/Documentation/DocBook/tracepoint.tmpl
@@ -0,0 +1,89 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
+ "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []>
+
+<book id="Tracepoints">
+ <bookinfo>
+ <title>The Linux Kernel Tracepoint API</title>
+
+ <authorgroup>
+ <author>
+ <firstname>Jason</firstname>
+ <surname>Baron</surname>
+ <affiliation>
+ <address>
+ <email>jbaron@redhat.com</email>
+ </address>
+ </affiliation>
+ </author>
+ </authorgroup>
+
+ <legalnotice>
+ <para>
+ This documentation is free software; you can redistribute
+ it and/or modify it under the terms of the GNU General Public
+ License as published by the Free Software Foundation; either
+ version 2 of the License, or (at your option) any later
+ version.
+ </para>
+
+ <para>
+ This program is distributed in the hope that it will be
+ useful, but WITHOUT ANY WARRANTY; without even the implied
+ warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ See the GNU General Public License for more details.
+ </para>
+
+ <para>
+ You should have received a copy of the GNU General Public
+ License along with this program; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ MA 02111-1307 USA
+ </para>
+
+ <para>
+ For more details see the file COPYING in the source
+ distribution of Linux.
+ </para>
+ </legalnotice>
+ </bookinfo>
+
+ <toc></toc>
+ <chapter id="intro">
+ <title>Introduction</title>
+ <para>
+ Tracepoints are static probe points that are located in strategic points
+ throughout the kernel. 'Probes' register/unregister with tracepoints
+ via a callback mechanism. The 'probes' are strictly typed functions that
+ are passed a unique set of parameters defined by each tracepoint.
+ </para>
+
+ <para>
+ From this simple callback mechanism, 'probes' can be used to profile, debug,
+ and understand kernel behavior. There are a number of tools that provide a
+ framework for using 'probes'. These tools include Systemtap, ftrace, and
+ LTTng.
+ </para>
+
+ <para>
+ Tracepoints are defined in a number of header files via various macros. Thus,
+ the purpose of this document is to provide a clear accounting of the available
+ tracepoints. The intention is to understand not only what tracepoints are
+ available but also to understand where future tracepoints might be added.
+ </para>
+
+ <para>
+ The API presented has functions of the form:
+ <function>trace_tracepointname(function parameters)</function>. These are the
+ tracepoints callbacks that are found throughout the code. Registering and
+ unregistering probes with these callback sites is covered in the
+ <filename>Documentation/trace/*</filename> directory.
+ </para>
+ </chapter>
+
+ <chapter id="irq">
+ <title>IRQ</title>
+!Iinclude/trace/events/irq.h
+ </chapter>
+
+</book>
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index f08e2bebb186..4a3c2209a124 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -56,7 +56,6 @@ parameter is applicable:
ISAPNP ISA PnP code is enabled.
ISDN Appropriate ISDN support is enabled.
JOY Appropriate joystick support is enabled.
- KMEMTRACE kmemtrace is enabled.
LIBATA Libata driver is enabled
LP Printer support is enabled.
LOOP Loopback device support is enabled.
@@ -754,12 +753,25 @@ and is between 256 and 4096 characters. It is defined in the file
ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
ftrace=[tracer]
- [ftrace] will set and start the specified tracer
+ [FTRACE] will set and start the specified tracer
as early as possible in order to facilitate early
boot debugging.
ftrace_dump_on_oops
- [ftrace] will dump the trace buffers on oops.
+ [FTRACE] will dump the trace buffers on oops.
+
+ ftrace_filter=[function-list]
+ [FTRACE] Limit the functions traced by the function
+ tracer at boot up. function-list is a comma separated
+ list of functions. This list can be changed at run
+ time by the set_ftrace_filter file in the debugfs
+ tracing directory.
+
+ ftrace_notrace=[function-list]
+ [FTRACE] Do not trace the functions specified in
+ function-list. This list can be changed at run time
+ by the set_ftrace_notrace file in the debugfs
+ tracing directory.
gamecon.map[2|3]=
[HW,JOY] Multisystem joystick and NES/SNES/PSX pad
@@ -1056,15 +1068,6 @@ and is between 256 and 4096 characters. It is defined in the file
use the HighMem zone if it exists, and the Normal
zone if it does not.
- kmemtrace.enable= [KNL,KMEMTRACE] Format: { yes | no }
- Controls whether kmemtrace is enabled
- at boot-time.
-
- kmemtrace.subbufs=n [KNL,KMEMTRACE] Overrides the number of
- subbufs kmemtrace's relay channel has. Set this
- higher than default (KMEMTRACE_N_SUBBUFS in code) if
- you experience buffer overruns.
-
kgdboc= [HW] kgdb over consoles.
Requires a tty driver that supports console polling.
(only serial suported for now)
diff --git a/Documentation/trace/events.txt b/Documentation/trace/events.txt
new file mode 100644
index 000000000000..f157d7594ea7
--- /dev/null
+++ b/Documentation/trace/events.txt
@@ -0,0 +1,90 @@
+ Event Tracing
+
+ Documentation written by Theodore Ts'o
+ Updated by Li Zefan
+
+1. Introduction
+===============
+
+Tracepoints (see Documentation/trace/tracepoints.txt) can be used
+without creating custom kernel modules to register probe functions
+using the event tracing infrastructure.
+
+Not all tracepoints can be traced using the event tracing system;
+the kernel developer must provide code snippets which define how the
+tracing information is saved into the tracing buffer, and how the
+tracing information should be printed.
+
+2. Using Event Tracing
+======================
+
+2.1 Via the 'set_event' interface
+---------------------------------
+
+The events which are available for tracing can be found in the file
+/debug/tracing/available_events.
+
+To enable a particular event, such as 'sched_wakeup', simply echo it
+to /debug/tracing/set_event. For example:
+
+ # echo sched_wakeup >> /debug/tracing/set_event
+
+[ Note: '>>' is necessary, otherwise it will firstly disable
+ all the events. ]
+
+To disable an event, echo the event name to the set_event file prefixed
+with an exclamation point:
+
+ # echo '!sched_wakeup' >> /debug/tracing/set_event
+
+To disable all events, echo an empty line to the set_event file:
+
+ # echo > /debug/tracing/set_event
+
+To enable all events, echo '*:*' or '*:' to the set_event file:
+
+ # echo *:* > /debug/tracing/set_event
+
+The events are organized into subsystems, such as ext4, irq, sched,
+etc., and a full event name looks like this: <subsystem>:<event>. The
+subsystem name is optional, but it is displayed in the available_events
+file. All of the events in a subsystem can be specified via the syntax
+"<subsystem>:*"; for example, to enable all irq events, you can use the
+command:
+
+ # echo 'irq:*' > /debug/tracing/set_event
+
+2.2 Via the 'enable' toggle
+---------------------------
+
+The events available are also listed in /debug/tracing/events/ hierarchy
+of directories.
+
+To enable event 'sched_wakeup':
+
+ # echo 1 > /debug/tracing/events/sched/sched_wakeup/enable
+
+To disable it:
+
+ # echo 0 > /debug/tracing/events/sched/sched_wakeup/enable
+
+To enable all events in sched subsystem:
+
+ # echo 1 > /debug/tracing/events/sched/enable
+
+To eanble all events:
+
+ # echo 1 > /debug/tracing/events/enable
+
+When reading one of these enable files, there are four results:
+
+ 0 - all events this file affects are disabled
+ 1 - all events this file affects are enabled
+ X - there is a mixture of events enabled and disabled
+ ? - this file does not affect any event
+
+3. Defining an event-enabled tracepoint
+=======================================
+
+See The example provided in samples/trace_events
+
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index e362f50c496f..2a82d8602944 100644
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -179,7 +179,7 @@ Here is the list of current tracers that may be configured.
Function call tracer to trace all kernel functions.
- "function_graph_tracer"
+ "function_graph"
Similar to the function tracer except that the
function tracer probes the functions on their entry
diff --git a/Documentation/trace/power.txt b/Documentation/trace/power.txt
new file mode 100644
index 000000000000..cd805e16dc27
--- /dev/null
+++ b/Documentation/trace/power.txt
@@ -0,0 +1,17 @@
+The power tracer collects detailed information about C-state and P-state
+transitions, instead of just looking at the high-level "average"
+information.
+
+There is a helper script found in scrips/tracing/power.pl in the kernel
+sources which can be used to parse this information and create a
+Scalable Vector Graphics (SVG) picture from the trace data.
+
+To use this tracer:
+
+ echo 0 > /sys/kernel/debug/tracing/tracing_enabled
+ echo power > /sys/kernel/debug/tracing/current_tracer
+ echo 1 > /sys/kernel/debug/tracing/tracing_enabled
+ sleep 1
+ echo 0 > /sys/kernel/debug/tracing/tracing_enabled
+ cat /sys/kernel/debug/tracing/trace | \
+ perl scripts/tracing/power.pl > out.sv