Commit Graph

27 Commits

Author SHA1 Message Date
Kirill Tkhai 8875125efe sched: Transform resched_task() into resched_curr()
We always use resched_task() with rq->curr argument.
It's not possible to reschedule any task but rq's current.

The patch introduces resched_curr(struct rq *) to
replace all of the repeating patterns. The main aim
is cleanup, but there is a little size profit too:

  (before)
	$ size kernel/sched/built-in.o
	   text	   data	    bss	    dec	    hex	filename
	155274	  16445	   7042	 178761	  2ba49	kernel/sched/built-in.o

	$ size vmlinux
	   text	   data	    bss	    dec	    hex	filename
	7411490	1178376	 991232	9581098	 92322a	vmlinux

  (after)
	$ size kernel/sched/built-in.o
	   text	   data	    bss	    dec	    hex	filename
	155130	  16445	   7042	 178617	  2b9b9	kernel/sched/built-in.o

	$ size vmlinux
	   text	   data	    bss	    dec	    hex	filename
	7411362	1178376	 991232	9580970	 9231aa	vmlinux

	I was choosing between resched_curr() and resched_rq(),
	and the first name looks better for me.

A little lie in Documentation/trace/ftrace.txt. I have not
actually collected the tracing again. With a hope the patch
won't make execution times much worse :)

Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20140628200219.1778.18735.stgit@localhost
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 13:38:19 +02:00
Robert Elliott 607e3a2920 tracing: Add funcgraph_tail option to print function name after closing braces
In the function-graph tracer, add a funcgraph_tail option
to print the function name on all } lines, not just
functions whose first line is no longer in the trace
buffer.

If a function calls other traced functions, its total
time appears on its } line.  This change allows grep
to be used to determine the function for which the
line corresponds.

Update Documentation/trace/ftrace.txt to describe
this new option.

Link: http://lkml.kernel.org/p/20140520221041.8359.6782.stgit@beardog.cce.hp.com

Signed-off-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-20 23:29:32 -04:00
Peter Zijlstra e5137b50a0 ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHED
Since the introduction of PREEMPT_NEED_RESCHED in:

  f27dde8dee ("sched: Add NEED_RESCHED to the preempt_count")

we need to be able to look at both TIF_NEED_RESCHED and
PREEMPT_NEED_RESCHED to understand the full preemption behaviour.

Add it to the trace output.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Link: http://lkml.kernel.org/r/20131004152826.GP3081@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-11 12:43:39 +01:00
Jingoo Han 0ab943bf56 Documentation: replace strict_strtoul() with kstrtoul()
The usage of strict_strtoul() is not preferred, because
strict_strtoul() is obsolete. Thus, kstrtoul() should be
used.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-08-20 12:56:26 +02:00
Steven Rostedt (Red Hat) 90e3c03c3a tracing: Add function probe to trigger a ftrace dump of current CPU trace
Add the "cpudump" command to have the current CPU ftrace buffer dumped
to console if a function is hit. This is useful when debugging a
tripple fault, where you have an idea of a function that is called
just before the tripple fault occurs, and can tell ftrace to dump its
content out to the console before it continues.

This differs from the "dump" command as it only dumps the content of
the ring buffer for the currently executing CPU, and does not show
the contents of the other CPUs.

Format is:

  <function>:cpudump

echo 'bad_address:cpudump' > /debug/tracing/set_ftrace_filter

To remove this:

echo '!bad_address:cpudump' > /debug/tracing/set_ftrace_filter

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-06-11 18:38:48 -04:00
Steven Rostedt (Red Hat) ad71d889b8 tracing: Add function probe to trigger a ftrace dump to console
Add the "dump" command to have the ftrace buffer dumped to console if
a function is hit. This is useful when debugging a tripple fault,
where you have an idea of a function that is called just before the
tripple fault occurs, and can tell ftrace to dump its content out
to the console before it continues.

Format is:

  <function>:dump

echo 'bad_address:dump' > /debug/tracing/set_ftrace_filter

To remove this:

echo '!bad_address:dump' > /debug/tracing/set_ftrace_filter

Requested-by: Luis Claudio R. Goncalves <lclaudio@uudg.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-06-11 18:38:46 -04:00
Steven Rostedt (Red Hat) 8d016091d1 tracing: Bring Documentation/trace/ftrace.txt up to date
The ftrace.txt document has been suffering from some serious bit rot.

Updated the current content to how things are as of v3.10.
Remove things that no longer exist.
Add documentation about new features:
  per_cpu
  stats
  instances
  stack trace
  etc.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-03-15 00:36:10 -04:00
Hiraku Toyooka 1abccd7419 tracing: update documentation of snapshot utility
Now, "snapshot" file returns success on a reset of snapshot buffer
even if the buffer wasn't allocated, instead of returning EINVAL.
This patch updates snapshot desctiption according to the change.

Link: http://lkml.kernel.org/r/51399409.4090207@hitachi.com

Signed-off-by: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-03-08 06:27:11 -05:00
Hiraku Toyooka c1043fcda1 tracing: Add documentation of snapshot utility
This patch adds snapshot description in ftrace documentation.
This description includes what the snapshot is and how to use it.

Link: http://lkml.kernel.org/r/20121226025309.3252.150.stgit@liselsia

Cc: Rob Landley <rob@landley.net>
Signed-off-by: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-01-30 11:02:07 -05:00
Geunsik Lim cdfb0d30e9 ftrace: Append wakeup_rt description of ftrace doc
Append and update the description about wakeup/wakeup_rt usage.

Link: http://lkml.kernel.org/r/1328695537-15081-2-git-send-email-geunsik.lim@gmail.com

Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Geunsik Lim <geunsik.lim@samsung.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-02-13 09:14:48 -05:00
David Sharp 750912fa36 tracing: Add an 'overwrite' trace_option.
Add an "overwrite" trace_option for ftrace to control whether the buffer should
be overwritten on overflow or not. The default remains to overwrite old events
when the buffer is full. This patch adds the option to instead discard newest
events when the buffer is full. This is useful to get a snapshot of traces just
after enabling traces. Dropping the current event is also a simpler code path.

Signed-off-by: David Sharp <dhsharp@google.com>
LKML-Reference: <1291844807-15481-1-git-send-email-dhsharp@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-09 13:52:27 -05:00
Steven Rostedt 6752ab4a9c tracing: Deprecate tracing_enabled for tracing_on
tracing_enabled should not be used, it is heavy weight and does not
do much in helping lower the overhead.

tracing_on should be used instead. Warn users to use tracing_on
when tracing_enabled is used as it will soon be removed from the
tracing directory.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-08 17:14:58 -05:00
Steven Rostedt 87d80de280 tracing: Remove obsolete sched_switch tracer
The trace events sched_switch and sched_wakeup do the same thing
as the stand alone sched_switch tracer does. It is no longer needed.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-08 17:14:56 -05:00
Chase Douglas 07271aa42d tracing: Add documentation for trace commands mod, traceon/traceoff
The mod command went in as commit
64e7c44061

The traceon/traceoff commands went in as commit
23b4ff3aa4

Signed-off-by: Chase Douglas <chase.douglas@canonical.com>
LKML-Reference: <1272045759-32018-1-git-send-email-chase.douglas@canonical.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-04-27 16:51:49 -04:00
Frederic Weisbecker cecbca96da tracing: Dump either the oops's cpu source or all cpus buffers
The ftrace_dump_on_oops kernel parameter, sysctl and sysrq let one
dump every cpu buffers when an oops or panic happens.

It's nice when you have few cpus but it may take ages if have many,
plus you miss the real origin of the problem in all the cpu traces.

Sometimes, all you need is to dump the cpu buffer that triggered the
opps, most of the time it is our main interest.

This patch modifies ftrace_dump_on_oops to handle this choice.

The ftrace_dump_on_oops kernel parameter, when it comes alone, has
the same behaviour than before. But ftrace_dump_on_oops=orig_cpu
will only dump the buffer of the cpu that oops'ed.

Similarly, sysctl kernel.ftrace_dump_on_oops=1 and
echo 1 > /proc/sys/kernel/ftrace_dump_on_oops keep their previous
behaviour. But setting 2 jumps into cpu origin dump mode.

v2: Fix double setup
v3: Fix spelling issues reported by Randy Dunlap
v4: Also update __ftrace_dump in the selftests

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
2010-04-21 23:11:42 +02:00
Daniel Mack 3ad2f3fbb9 tree-wide: Assorted spelling fixes
In particular, several occurances of funny versions of 'success',
'unknown', 'therefore', 'acknowledge', 'argument', 'achieve', 'address',
'beginning', 'desirable', 'separate' and 'necessary' are fixed.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Joe Perches <joe@perches.com>
Cc: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-02-09 11:13:56 +01:00
Yang Hongyang 6993b1bb1e tracing/documentation: Fix a typo in ftrace.txt
'ftrace' is no longer the name of the function tracer, to activate
the function trace 'echo function > current_tracer' is to be used instead
of 'echo ftrace > current_tracer'. Update the documentation to reflect
the current implementation.

Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
LKML-Reference: <4B5D0BA8.20106@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-26 16:59:33 -05:00
Jiri Olsa 67b394f7f2 tracing: Fix comment typo and documentation example
Trivial patch to fix a documentation example and to fix a
comment.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091023233646.871719877@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-24 11:07:50 +02:00
Uwe Kleine-Koenig 3dbda77e6f trivial: fix typos "man[ae]g?ment" -> "management"
Signed-off-by: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-09-21 15:14:56 +02:00
Mike Frysinger 555f386c98 ftrace: document function and function graph implementation
While implementing function tracer and function tracer graph support,
I found the exact arch implementation details to be a bit lacking
(and my x86 foo ain't great).  So after pounding out support for
the Blackfin arch, start documenting the requirements/details.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
LKML-Reference: <1252973415-21264-1-git-send-email-vapier@gentoo.org>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-14 21:43:15 -04:00
Albin Tonnerre 4a88d44ab1 tracing: Remove mentioning of legacy latency_trace file from documentation
The latency_trace file got removed a while back by commit
886b5b73d7 and has been replaced
by the latency-format option.

This patch fixes the documentation by reflecting this change.

Changes since v1:
 - mention that the trace format is configurable through the
   latency-format option
 - Fix a couple mistakes related to the timestamps

Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20090831204007.GE4237@pc-ras4041.res.insa>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-04 23:30:38 +02:00
GeunSik Lim 156f5a7801 debugfs: Fix terminology inconsistency of dir name to mount debugfs filesystem.
Many developers use "/debug/" or "/debugfs/" or "/sys/kernel/debug/"
directory name to mount debugfs filesystem for ftrace according to
./Documentation/tracers/ftrace.txt file.

And, three directory names(ex:/debug/, /debugfs/, /sys/kernel/debug/) is
existed in kernel source like ftrace, DRM, Wireless, Documentation,
Network[sky2]files to mount debugfs filesystem.

debugfs means debug filesystem for debugging easy to use by greg kroah
hartman. "/sys/kernel/debug/" name is suitable as directory name
of debugfs filesystem.
- debugfs related reference: http://lwn.net/Articles/334546/

Fix inconsistency of directory name to mount debugfs filesystem.

* From Steven Rostedt
  - find_debugfs() and tracing_files() in this patch.

Signed-off-by: GeunSik Lim <geunsik.lim@samsung.com>
Acked-by     : Inaky Perez-Gonzalez <inaky@linux.intel.com>
Reviewed-by  : Steven Rostedt <rostedt@goodmis.org>
Reviewed-by  : James Smart <james.smart@emulex.com>
CC: Jiri Kosina <trivial@kernel.org>
CC: David Airlie <airlied@linux.ie>
CC: Peter Osterlund <petero2@telia.com>
CC: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
CC: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
CC: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15 21:30:28 -07:00
GeunSik Lim baf20b3e51 trivial: ftrace:fix description of trace directory
Fix trace source directory from kernel/tracing/ to kernel/trace/.

Signed-off-by: GeunSik Lim <geunsik.lim@samsung.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-06-12 18:01:49 +02:00
Linus Torvalds 8623661180 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
  ...
2009-06-10 19:53:40 -07:00
Mike Frysinger bc5c6c043d ftrace/documentation: fix typo in function grapher name
The function graph tracer is called just "function_graph" (no trailing
"_tracer" needed).

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
LKML-Reference: <1244623722-6325-1-git-send-email-vapier@gentoo.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-10 13:06:25 -04:00
GeunSik Lim 294ae40115 ftrace: fix typo about map of kernel priority in ftrace.txt file.
Fix typo about chart to map the kernel priority to user land priorities.

   * About sched_setscheduler(2)
      Processes scheduled under SCHED_FIFO or SCHED_RR
      can have a (user-space) static priority in the range 1 to 99.
      (reference: http://www.kernel.org/doc/man-pages/online/pages/
                  man2/sched_setscheduler.2.html)

   * From: Steven Rostedt
      0 to 98 - maps to RT tasks 99 to 1 (SCHED_RR or SCHED_FIFO)

      99 - maps to internal kernel threads that want to be lower than RT tasks
      but higher than SCHED_OTHER tasks. Although I'm not sure if any
      kernel thread actually uses this. I'm not even sure how this can be
      set, because the internal sched_setscheduler function does not allow
      for it.

      100 to 139 - maps nice levels -20 to 19. These are not set via
      sched_setscheduler, but are set via the nice system call.

      140 - reserved for idle tasks.

Signed-off-by: GeunSik Lim <geunsik.lim@samsung.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-29 16:21:08 +02:00
Li Zefan 66bb74888e tracing: consolidate documents
Move kmemtrace.txt, tracepoints.txt, ftrace.txt and mmiotrace.txt to
the new trace/ directory.

I didnt find any references to those documents in both source
files and documents, so no extra work needs to be done.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Pekka Paalanen <pq@iki.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
LKML-Reference: <49DD6E2B.6090200@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-09 07:28:10 +02:00