Commit Graph

143286 Commits

Author SHA1 Message Date
Steven Rostedt
9ae5b87900 tracing: change branch profiling to a choice selection
This patch makes the branch profiling into a choice selection:

  None               - no branch profiling
  likely/unlikely    - only profile likely/unlikely branches
  all                - profile all branches

The all profiler will also enable the likely/unlikely branches.

This does not change the way the profiler works or the dependencies
between the profilers.

What this patch does, is keep the branch profiling from being selected
by an allyesconfig make. The branch profiler is very intrusive and
it is known to break various architecture builds when selected as an
allyesconfig.

[ Impact: prevent branch profiler from being selected in allyesconfig ]

Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-20 11:07:48 -04:00
Frederic Weisbecker
f3b9aae162 tracing/ring-buffer: Add unlock recursion protection on discard
The pair of helpers trace_recursive_lock() and trace_recursive_unlock()
have been introduced recently to provide generic tracing recursion
protection.

They are used in a symetric way:

 - trace_recursive_lock() on buffer reserve
 - trace_recursive_unlock() on buffer commit

However sometimes, we don't commit but discard on entry
to the buffer, ie: in case of filter checking.

Then we must also unlock the recursion protection on discard time,
otherwise the tracing gets definitely deactivated and a warning
is raised spuriously, such as:

111.119821] ------------[ cut here ]------------
[  111.119829] WARNING: at kernel/trace/ring_buffer.c:1498 ring_buffer_lock_reserve+0x1b7/0x1d0()
[  111.119835] Hardware name: AMILO Li 2727
[  111.119839] Modules linked in:
[  111.119846] Pid: 5731, comm: Xorg Tainted: G        W  2.6.30-rc1 #69
[  111.119851] Call Trace:
[  111.119863]  [<ffffffff8025ce68>] warn_slowpath+0xd8/0x130
[  111.119873]  [<ffffffff8028a30f>] ? __lock_acquire+0x19f/0x1ae0
[  111.119882]  [<ffffffff8028a30f>] ? __lock_acquire+0x19f/0x1ae0
[  111.119891]  [<ffffffff802199b0>] ? native_sched_clock+0x20/0x70
[  111.119899]  [<ffffffff80286dee>] ? put_lock_stats+0xe/0x30
[  111.119906]  [<ffffffff80286eb8>] ? lock_release_holdtime+0xa8/0x150
[  111.119913]  [<ffffffff802c8ae7>] ring_buffer_lock_reserve+0x1b7/0x1d0
[  111.119921]  [<ffffffff802cd110>] trace_buffer_lock_reserve+0x30/0x70
[  111.119930]  [<ffffffff802ce000>] trace_current_buffer_lock_reserve+0x20/0x30
[  111.119939]  [<ffffffff802474e8>] ftrace_raw_event_sched_switch+0x58/0x100
[  111.119948]  [<ffffffff808103b7>] __schedule+0x3a7/0x4cd
[  111.119957]  [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b
[  111.119964]  [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b
[  111.119971]  [<ffffffff80810c08>] schedule+0x18/0x40
[  111.119977]  [<ffffffff80810e09>] preempt_schedule+0x39/0x60
[  111.119985]  [<ffffffff80813bd3>] _read_unlock+0x53/0x60
[  111.119993]  [<ffffffff807259d2>] sock_def_readable+0x72/0x80
[  111.120002]  [<ffffffff807ad5ed>] unix_stream_sendmsg+0x24d/0x3d0
[  111.120011]  [<ffffffff807219a3>] sock_aio_write+0x143/0x160
[  111.120019]  [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b
[  111.120026]  [<ffffffff80721860>] ? sock_aio_write+0x0/0x160
[  111.120033]  [<ffffffff80721860>] ? sock_aio_write+0x0/0x160
[  111.120042]  [<ffffffff8031c283>] do_sync_readv_writev+0xf3/0x140
[  111.120049]  [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b
[  111.120057]  [<ffffffff80276ff0>] ? autoremove_wake_function+0x0/0x40
[  111.120067]  [<ffffffff8045d489>] ? cap_file_permission+0x9/0x10
[  111.120074]  [<ffffffff8045c1e6>] ? security_file_permission+0x16/0x20
[  111.120082]  [<ffffffff8031cab4>] do_readv_writev+0xd4/0x1f0
[  111.120089]  [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b
[  111.120097]  [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b
[  111.120105]  [<ffffffff8031cc18>] vfs_writev+0x48/0x70
[  111.120111]  [<ffffffff8031cd65>] sys_writev+0x55/0xc0
[  111.120119]  [<ffffffff80211e32>] system_call_fastpath+0x16/0x1b
[  111.120125] ---[ end trace 15605f4e98d5ccb5 ]---

[ Impact: fix spurious warning triggering tracing shutdown ]

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-04-20 10:59:20 +02:00
Frederic Weisbecker
e057a5e564 tracing/core: Add current context on tracing recursion warning
In case of tracing recursion detection, we only get the stacktrace.
But the current context may be very useful to debug the issue.

This patch adds the softirq/hardirq/nmi context with the warning
using lockdep context display to have a familiar output.

v2: Use printk_once()
v3: drop {hardirq,softirq}_context which depend on lockdep,
    only keep what is part of current->trace_recursion,
    sufficient to debug the warning source.

[ Impact: print context necessary to debug recursion ]

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-04-19 23:38:12 +02:00
Steven Rostedt
8e668b5b34 tracing: remove format attribute of inline function
Due to a cut and paste error, I added the gcc attribute for printf
format to the static inline stub of trace_seq_printf.

This will cause a compile failure.

[ Impact: fix compiler error when CONFIG_TRACING is off ]

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: =?ISO-8859-15?Q?Fr=E9d=E9ric_Weisbecker?= <fweisbec@gmail.com>
LKML-Reference: <alpine.DEB.2.00.0904171717080.1016@gandalf.stny.rr.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-18 09:49:10 +02:00
Steven Rostedt
3189cdb316 tracing: protect trace_printk from recursion
trace_printk can be called from any context, including NMIs.
If this happens, then we must test for for recursion before
grabbing any spinlocks.

This patch prevents trace_printk from being called recursively.

[ Impact: prevent hard lockup in lockdep event tracer ]

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-17 16:21:35 -04:00
Steven Rostedt
261842b7c9 tracing: add same level recursion detection
The tracing infrastructure allows for recursion. That is, an interrupt
may interrupt the act of tracing an event, and that interrupt may very well
perform its own trace. This is a recursive trace, and is fine to do.

The problem arises when there is a bug, and the utility doing the trace
calls something that recurses back into the tracer. This recursion is not
caused by an external event like an interrupt, but by code that is not
expected to recurse. The result could be a lockup.

This patch adds a bitmask to the task structure that keeps track
of the trace recursion. To find the interrupt depth, the following
algorithm is used:

  level = hardirq_count() + softirq_count() + in_nmi;

Here, level will be the depth of interrutps and softirqs, and even handles
the nmi. Then the corresponding bit is set in the recursion bitmask.
If the bit was already set, we know we had a recursion at the same level
and we warn about it and fail the writing to the buffer.

After the data has been committed to the buffer, we clear the bit.
No atomics are needed. The only races are with interrupts and they reset
the bitmask before returning anywy.

[ Impact: detect same irq level trace recursion ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-17 16:21:32 -04:00
Steven Rostedt
12acd473d4 tracing: add EXPORT_SYMBOL_GPL for trace commits
Not all the necessary symbols were exported to allow for tracing
by modules. This patch adds them in.

[ Impact: allow modules to commit data to the ring buffer ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-17 16:21:28 -04:00
Steven Rostedt
b0afdc126d tracing/events: enable code with EVENT_TRACING not EVENT_TRACER
The CONFIG_EVENT_TRACER is the way to turn on event tracing when no
other tracing has been configured. All code to get enabled should
depend on CONFIG_EVENT_TRACING. That is what is enabled when TRACING
(or CONFIG_EVENT_TRACER) is selected.

This patch enables the include/trace/ftrace.h file when
CONFIG_EVENT_TRACING is enabled.

[ Impact: fix warning in event tracer selftest ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-17 16:20:16 -04:00
Tom Zanussi
ac1adc55fc tracing/filters: add filter_mutex to protect filter predicates
This patch adds a filter_mutex to prevent the filter predicates from
being accessed concurrently by various external functions.

It's based on a previous patch by Li Zefan:
        "[PATCH 7/7] tracing/filters: make filter preds RCU safe"

v2 changes:

- fixed wrong value returned in a add_subsystem_pred() failure case
  noticed by Li Zefan.

[ Impact: fix trace filter corruption/crashes on parallel access ]

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Tested-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: paulmck@linux.vnet.ibm.com
LKML-Reference: <1239946028.6639.13.camel@tropicana>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-17 18:28:27 +02:00
Zhaolei
46de405f25 tracing: Remove include/trace/kmem_event_types.h
kmem_event_types.h is no longer necessary since tracepoint definitions
are put into include/trace/events/kmem.h

[ Impact: remove now-unused file. ]

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <49E7EF37.2080205@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-17 18:26:42 +02:00
Li Zefan
339ae5d3c3 tracing: fix file mode of trace and README
trace is read-write and README is read-only.

[ Impact: fix /debug/tracing/ file permissions. ]

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <49E7EAB6.4070605@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-17 18:04:36 +02:00
Jeremy Fitzhardinge
76aa81118d tracing: avoid warnings from zero-arg tracepoints
Tracepoints with no arguments can issue two warnings:

	"field" defined by not used
	"ret" is uninitialized in this function

Mark field as being OK to leave unused, and initialize ret.

[ Impact: fix false positive compiler warnings. ]

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: mathieu.desnoyers@polymtl.ca
LKML-Reference: <1239950139-1119-5-git-send-email-jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-17 17:52:26 +02:00
Steven Rostedt
9ea21c1ecd tracing/events: perform function tracing in event selftests
We can find some bugs in the trace events if we stress the writes as well.
The function tracer is a good way to stress the events.

[ Impact: extend scope of event tracer self-tests ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20090416161746.604786131@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-17 17:10:35 +02:00
Avadh Patel
69abe6a5d1 tracing: add saved_cmdlines file to show cached task comms
Export the cached task comms to userspace. This allows user apps to translate
the pids from a trace into their respective task command lines.

[ Impact: let userspace apps reading binary buffer know comm's of pids ]

Signed-off-by: Avadh Patel <avadh4all@gmail.com>
[ added error checking and use of buf pointer to index file_buf ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-17 17:04:12 +02:00
Steven Rostedt
d1b182a8d4 tracing/events/ring-buffer: expose format of ring buffer headers to users
Currently, every thing needed to read the binary output from the
ring buffers is available, with the exception of the way the ring
buffers handles itself internally.

This patch creates two special files in the debugfs/tracing/events
directory:

 # cat /debug/tracing/events/header_page
        field: u64 timestamp;   offset:0;       size:8;
        field: local_t commit;  offset:8;       size:8;
        field: char data;       offset:16;      size:4080;

 # cat /debug/tracing/events/header_event
        type        :    2 bits
        len         :    3 bits
        time_delta  :   27 bits
        array       :   32 bits

        padding     : type == 0
        time_extend : type == 1
        data        : type == 3

This is to allow a userspace app to see if the ring buffer format changes
or not.

[ Impact: allow userspace apps to know of ringbuffer format changes ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-17 17:03:28 +02:00
Steven Rostedt
e6187007d6 tracing/events: add startup tests for events
As events start to become popular, and the new way to add tracing
infrastructure into ftrace, it is important to catch any problems
that might happen with a mistake in the TRACE_EVENT macro.

This patch introduces a startup self test on the registered trace
events. Note, it can only do a generic test, any type of testing that
needs more involement is needed to be implemented by the tracepoint
creators.

The test goes down one by one enabling a trace point and running
some random tasks (random in the sense that I just made them up).
Those tasks are creating threads, grabbing mutexes and spinlocks
and using workqueues.

After testing each event individually, it does the same test after
enabling each system of trace points. Like sched, irq, lockdep.

Then finally it enables all tracepoints and performs the tasks again.
The output to the console on bootup will look like this when everything
works:

Running tests on trace events:
Testing event kfree_skb: OK
Testing event kmalloc: OK
Testing event kmem_cache_alloc: OK
Testing event kmalloc_node: OK
Testing event kmem_cache_alloc_node: OK
Testing event kfree: OK
Testing event kmem_cache_free: OK
Testing event irq_handler_exit: OK
Testing event irq_handler_entry: OK
Testing event softirq_entry: OK
Testing event softirq_exit: OK
Testing event lock_acquire: OK
Testing event lock_release: OK
Testing event sched_kthread_stop: OK
Testing event sched_kthread_stop_ret: OK
Testing event sched_wait_task: OK
Testing event sched_wakeup: OK
Testing event sched_wakeup_new: OK
Testing event sched_switch: OK
Testing event sched_migrate_task: OK
Testing event sched_process_free: OK
Testing event sched_process_exit: OK
Testing event sched_process_wait: OK
Testing event sched_process_fork: OK
Testing event sched_signal_send: OK
Running tests on trace event systems:
Testing event system skb: OK
Testing event system kmem: OK
Testing event system irq: OK
Testing event system lockdep: OK
Testing event system sched: OK
Running tests on all trace events:
Testing all events: OK

[ folded in:

  tracing: add #include <linux/delay.h> to fix build failure in test_work()

  This build failure occured on a few rare configs:

   kernel/trace/trace_events.c: In function ‘test_work’:
   kernel/trace/trace_events.c:975: error: implicit declaration of function ‘udelay’
   kernel/trace/trace_events.c:980: error: implicit declaration of function ‘msleep’

  delay.h is included in way too many other headers, hiding cases
  where new usage is added without header inclusion.

  [ Impact: build fix ]

  Signed-off-by: Ingo Molnar <mingo@elte.hu>
]

[ Impact: add event tracer self-tests ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-17 17:01:37 +02:00
Steven Rostedt
93eb677d74 ftrace: use module notifier for function tracer
The hooks in the module code for the function tracer must be called
before any of that module code runs. The function tracer hooks
modify the module (replacing calls to mcount to nops). If the code
is executed while the change occurs, then the CPU can take a GPF.

To handle the above with a bit of paranoia, I originally implemented
the hooks as calls directly from the module code.

After examining the notifier calls, it looks as though the start up
notify is called before any of the module's code is executed. This makes
the use of the notify safe with ftrace.

Only the startup notify is required to be "safe". The shutdown simply
removes the entries from the ftrace function list, and does not modify
any code.

This change has another benefit. It removes a issue with a reverse dependency
in the mutexes of ftrace_lock and module_mutex.

[ Impact: fix lock dependency bug, cleanup ]

Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-17 16:59:15 +02:00
Li Zefan
f3948f8857 blktrace: fix context-info when mixed-using blk tracer and trace events
When current tracer is set to blk tracer, TRACE_ITER_CONTEXT_INFO is
unset, but actually context-info is printed:

    pdflush-431   [000]   821.181576:   8,0    P   N [pdflush]

And then if we enable TRACE_ITER_CONTEXT_INFO:

    # echo context-info > trace_options

We'll see context-info printed twice. What's worse, when we use blk
tracer and trace events at the same time, we'll see no context-info
for trace events at all:

    jbd2_commit_logging: dev dm-0:8 transaction 333227
    jbd2_end_commit: dev dm-0:8 transaction 333227 head 332814
      rm-25433 [001]  9578.307485:   8,18   m   N cfq25433 slice expired t=0
      rm-25433 [001]  9578.307486:   8,18   m   N cfq25433 put_queue

This patch adds blk_tracer->set_flags(), and context-info flag is unset
only when we set the output to classic mode.

Note after this patch, one should unset context-info explicitly if he
wants to get binary output that can be parsed by blkparse:

    # echo nocontext-info > trace_options
    # echo bin > trace_options
    # echo blk > current_tracer
    # cat trace_pipe | blkparse -i -

Reported-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <49E54E60.50408@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-16 10:11:01 +02:00
Li Zefan
1d54ad6da9 blktrace: add trace/ to /sys/block/sda
Impact: allow ftrace-plugin blktrace to trace device-mapper devices

To trace a single partition:
  # echo 1 > /sys/block/sda/sda1/enable

To trace the whole sda instead:
  # echo 1 > /sys/block/sda/enable

Thus we also fix an issue reported by Ted, that ftrace-plugin blktrace
can't be used to trace device-mapper devices.

Now:

  # echo 1 > /sys/block/dm-0/trace/enable
  echo: write error: No such device or address
  # mount -t ext4 /dev/dm-0 /mnt
  # echo 1 > /sys/block/dm-0/trace/enable
  # echo blk > /debug/tracing/current_tracer

Reported-by: Theodore Tso <tytso@mit.edu>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Shawn Du <duyuyang@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
LKML-Reference: <49E42665.6020506@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-16 10:10:59 +02:00
Li Zefan
9908c30997 blktrace: support per-partition tracing for ftrace plugin
The previous patch adds support to trace a single partition for
relay+ioctl blktrace, and this patch is for ftrace plugin blktrace:

  # echo 1 > /sys/block/sda/sda7/enable
  # cat start_lba
  102398373
  # cat end_lba
  102703545

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Shawn Du <duyuyang@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
LKML-Reference: <49E42646.4060608@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-16 10:10:58 +02:00
Shawn Du
d0deef5b14 blktrace: support per-partition tracing
Though one can specify '-d /dev/sda1' when using blktrace, it still
traces the whole sda.

To support per-partition tracing, when we start tracing, we initialize
bt->start_lba and bt->end_lba to the start and end sector of that
partition.

Note some actions are per device, thus we don't filter 0-sector events.

The original patch and discussion can be found here:
	http://marc.info/?l=linux-btrace&m=122949374214540&w=2

Signed-off-by: Shawn Du <duyuyang@gmail.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
LKML-Reference: <49E42620.4050701@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-16 10:10:57 +02:00
Steven Rostedt
9cfe06f8cd tracing/events: add trace-events-sample
This patch adds a sample to the samples directory on how to create
and use TRACE_EVENT trace points.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14 22:09:18 -04:00
Steven Rostedt
ad8d75fff8 tracing/events: move trace point headers into include/trace/events
Impact: clean up

Create a sub directory in include/trace called events to keep the
trace point headers in their own separate directory. Only headers that
declare trace points should be defined in this directory.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Zhao Lei <zhaolei@cn.fujitsu.com>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14 22:05:43 -04:00
Steven Rostedt
ecda8ae02a tracing/events: fix lockdep system name
Impact: fix compile error of lockdep event tracer

Ingo Molnar pointed out that the system name for the lockdep tracer was "lock"
which is used to include the event trace file name. It should be "lockdep"

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14 22:04:26 -04:00
Steven Rostedt
61f919a12f tracing/events: fix compile for modules disabled
Impact: compile fix

The addition of TRACE_EVENT for modules breaks the build for when
modules are disabled. This code fixes that.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14 22:04:19 -04:00
Steven Rostedt
6d723736e4 tracing/events: add support for modules to TRACE_EVENT
Impact: allow modules to add TRACE_EVENTS on load

This patch adds the final hooks to allow modules to use the TRACE_EVENT
macro. A notifier and a data structure are used to link the TRACE_EVENTs
defined in the module to connect them with the ftrace event tracing system.

It also adds the necessary automated clean ups to the trace events when a
module is removed.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14 12:58:03 -04:00
Steven Rostedt
17c873ec28 tracing/events: add export symbols for trace events in modules
Impact: let modules add trace events

The trace event code requires some functions to be exported to allow
modules to use TRACE_EVENT. This patch adds EXPORT_SYMBOL_GPL to the
necessary functions.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14 12:58:01 -04:00
Steven Rostedt
a59fd60272 tracing/events: convert event call sites to use a link list
Impact: makes it possible to define events in modules

The events are created by reading down the section that they are linked
in by the macros. But this is not scalable to modules. This patch converts
the manipulations to use a global link list, and on boot up it adds
the items in the section to the list.

This change will allow modules to add their tracing events to the list as
well.

Note, this change alone does not permit modules to use the TRACE_EVENT macros,
but the change is needed for them to eventually do so.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14 12:58:00 -04:00
Steven Rostedt
f42c85e74f tracing/events: move the ftrace event tracing code to core
This patch moves the ftrace creation into include/trace/ftrace.h and
simplifies the work of developers in adding new tracepoints.
Just the act of creating the trace points in include/trace and including
define_trace.h will create the events in the debugfs/tracing/events
directory.

This patch removes the need of include/trace/trace_events.h

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14 12:57:59 -04:00
Steven Rostedt
97f2025153 tracing/events: move declarations from trace directory to core include
In preparation to allowing trace events to happen in modules, we need
to move some of the local declarations in the kernel/trace directory
into include/linux.

This patch simply moves the declarations and performs no context changes.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14 12:57:58 -04:00
Steven Rostedt
9504504cba tracing: make trace_seq operations available for core kernel
In the process to make TRACE_EVENT macro work for modules, the trace_seq
operations must be available for core kernel code.

These operations are quite useful and can be used for other implementations.

The main idea is that we create a trace_seq handle that acts very much
like the seq_file handle.

	struct trace_seq *s = kmalloc(sizeof(*s, GFP_KERNEL);

	trace_seq_init(s);
	trace_seq_printf(s, "some data %d\n", variable);

	printk("%s", s->buffer);

The main use is to allow a top level function call several other functions
that may store printf like data into the buffer. Then at the end, the top
level function can process all the data with any method it would like to.
It could be passed to userspace, output via printk or even use seq_file:

	trace_seq_to_user(s, ubuf, cnt);
	seq_puts(m, s->buffer);

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14 12:57:57 -04:00
Steven Rostedt
a8d154b009 tracing: create automated trace defines
This patch lowers the number of places a developer must modify to add
new tracepoints. The current method to add a new tracepoint
into an existing system is to write the trace point macro in the
trace header with one of the macros TRACE_EVENT, TRACE_FORMAT or
DECLARE_TRACE, then they must add the same named item into the C file
with the macro DEFINE_TRACE(name) and then add the trace point.

This change cuts out the needing to add the DEFINE_TRACE(name).
Every file that uses the tracepoint must still include the trace/<type>.h
file, but the one C file must also add a define before the including
of that file.

 #define CREATE_TRACE_POINTS
 #include <trace/mytrace.h>

This will cause the trace/mytrace.h file to also produce the C code
necessary to implement the trace point.

Note, if more than one trace/<type>.h is used to create the C code
it is best to list them all together.

 #define CREATE_TRACE_POINTS
 #include <trace/foo.h>
 #include <trace/bar.h>
 #include <trace/fido.h>

Thanks to Mathieu Desnoyers and Christoph Hellwig for coming up with
the cleaner solution of the define above the includes over my first
design to have the C code include a "special" header.

This patch converts sched, irq and lockdep and skb to use this new
method.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Zhao Lei <zhaolei@cn.fujitsu.com>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14 12:57:28 -04:00
Steven Rostedt
ea20d9293c tracing: consolidate trace and trace_event headers
Impact: clean up

Neil Horman (et. al.) criticized the way the trace events were broken up
into two files. The reason for that was that ftrace needed to separate out
the declarations from where the #include <linux/tracepoint.h> was used.
It then dawned on me that the tracepoint.h header only needs to define the
TRACE_EVENT macro if it is not already defined.

The solution is simply to test if TRACE_EVENT is defined, and if it is not
then the linux/tracepoint.h header can define it. This change consolidates
all the <traces>.h and <traces>_event_types.h into the <traces>.h file.

Reported-by: Neil Horman <nhorman@tuxdriver.com>
Reported-by: Theodore Tso <tytso@mit.edu>
Reported-by: Jiaying Zhang <jiayingz@google.com>
Cc: Zhaolei <zhaolei@cn.fujitsu.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14 09:43:40 -04:00
Tom Zanussi
0a19e53c15 tracing/filters: allow on-the-fly filter switching
This patch allows event filters to be safely removed or switched
on-the-fly while avoiding the use of rcu or the suspension of tracing of
previous versions.

It does it by adding a new filter_pred_none() predicate function which
does nothing and by never deallocating either the predicates or any of
the filter_pred members used in matching; the predicate lists are
allocated and initialized during ftrace_event_calls initialization.

Whenever a filter is removed or replaced, the filter_pred_* functions
currently in use by the affected ftrace_event_call are immediately
switched over to to the filter_pred_none() function, while the rest of
the filter_pred members are left intact, allowing any currently
executing filter_pred_* functions to finish up, using the values they're
currently using.

In the case of filter replacement, the new predicate values are copied
into the old predicates after the above step, and the filter_pred_none()
functions are replaced by the filter_pred_* functions for the new
filter.  In this case, it is possible though very unlikely that a
previous filter_pred_* is still running even after the
filter_pred_none() switch and the switch to the new filter_pred_*.  In
that case, however, because nothing has been deallocated in the
filter_pred, the worst that can happen is that the old filter_pred_*
function sees the new values and as a result produces either a false
positive or a false negative, depending on the values it finds.

So one downside to this method is that rarely, it can produce a bad
match during the filter switch, but it should be possible to live with
that, IMHO.

The other downside is that at least in this patch the predicate lists
are always pre-allocated, taking up memory from the start.  They could
probably be allocated on first-use, and de-allocated when tracing is
completely stopped - if this patch makes sense, I could create another
one to do that later on.

Oh, and it also places a restriction on the size of __arrays in events,
currently set to 128, since they can't be larger than the now embedded
str_val arrays in the filter_pred struct.

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: paulmck@linux.vnet.ibm.com
LKML-Reference: <1239610670.6660.49.camel@tropicana>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 00:03:55 +02:00
Ingo Molnar
b5c851a88a Merge branch 'linus' into tracing/core
Merge reason: merge latest tracing fixes to avoid conflicts in
              kernel/trace/trace_events_filter.c with upcoming change

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 00:02:22 +02:00
Tom Zanussi
eb02ce017d tracing/filters: use ring_buffer_discard_commit() in filter_check_discard()
This patch changes filter_check_discard() to make use of the new
ring_buffer_discard_commit() function and modifies the current users to
call the old commit function in the non-discard case.

It also introduces a version of filter_check_discard() that uses the
global trace buffer (filter_current_check_discard()) for those cases.

v2 changes:

- fix compile error noticed by Ingo Molnar

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: fweisbec@gmail.com
LKML-Reference: <1239178554.10295.36.camel@tropicana>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 00:00:56 +02:00
Tom Zanussi
5f77a88b3f tracing/infrastructure: separate event tracer from event support
Add a new config option, CONFIG_EVENT_TRACING that gets selected
when CONFIG_TRACING is selected and adds everything needed by the stuff
in trace_export - basically all the event tracing support needed by e.g.
bprint, minus the actual events, which are only included if
CONFIG_EVENT_TRACER is selected.

So CONFIG_EVENT_TRACER can be used to turn on or off the generated events
(what I think of as the 'event tracer'), while CONFIG_EVENT_TRACING turns
on or off the base event tracing support used by both the event tracer and
the other things such as bprint that can't be configured out.

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: fweisbec@gmail.com
LKML-Reference: <1239178441.10295.34.camel@tropicana>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 00:00:55 +02:00
Steven Rostedt
77d9f465d4 tracing/filters: use ring_buffer_discard_commit for discarded events
The ring_buffer_discard_commit makes better usage of the ring_buffer
when an event has been discarded. It tries to remove it completely if
possible.

This patch converts the trace event filtering to use
ring_buffer_discard_commit instead of the ring_buffer_event_discard.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 00:00:54 +02:00
Steven Rostedt
fa1b47dd85 ring-buffer: add ring_buffer_discard_commit
The ring_buffer_discard_commit is similar to ring_buffer_event_discard
but it can only be done on an event that has yet to be commited.
Unpredictable results can happen otherwise.

The main difference between ring_buffer_discard_commit and
ring_buffer_event_discard is that ring_buffer_discard_commit will try
to free the data in the ring buffer if nothing has addded data
after the reserved event. If something did, then it acts almost the
same as ring_buffer_event_discard followed by a
ring_buffer_unlock_commit.

Note, either ring_buffer_commit_discard and ring_buffer_unlock_commit
can be called on an event, not both.

This commit also exports both discard functions to be usable by
GPL modules.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 00:00:53 +02:00
Tom Zanussi
e45f2e2bd2 tracing/filters: add TRACE_EVENT_FORMAT_NOFILTER event macro
Frederic Weisbecker suggested that the trace_special event shouldn't be
filterable; this patch adds a TRACE_EVENT_FORMAT_NOFILTER event macro
that allows an event format to be exported without having a filter
attached, and removes filtering from the trace_special event.

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 00:00:51 +02:00
Tom Zanussi
e1112b4d96 tracing/filters: add run-time field descriptions to TRACE_EVENT_FORMAT events
This patch adds run-time field descriptions to all the event formats
exported using TRACE_EVENT_FORMAT.  It also hooks up all the tracers
that use them (i.e. the tracers in the 'ftrace subsystem') so they can
also have their output filtered by the event-filtering mechanism.

When I was testing this, there were a couple of things that fooled me
into thinking the filters weren't working, when actually they were -
I'll mention them here so others don't make the same mistakes (and file
bug reports. ;-)

One is that some of the tracers trace multiple events e.g. the
sched_switch tracer uses the context_switch and wakeup events, and if
you don't set filters on all of the traced events, the unfiltered output
from the events without filters on them can make it look like the
filtering as a whole isn't working properly, when actually it is doing
what it was asked to do - it just wasn't asked to do the right thing.

The other is that for the really high-volume tracers e.g. the function
tracer, the volume of filtered events can be so high that it pushes the
unfiltered events out of the ring buffer before they can be read so e.g.
cat'ing the trace file repeatedly shows either no output, or once in
awhile some output but that isn't there the next time you read the
trace, which isn't what you normally expect when reading the trace file.
If you read from the trace_pipe file though, you can catch them before
they disappear.

Changes from v1:

As suggested by Frederic Weisbecker:

- get rid of externs in functions
- added unlikely() to filter_check_discard()

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 00:00:50 +02:00
Linus Torvalds
80a04d3f2f Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixes
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixes:
  docbook: make cleandocs
  kbuild: fix spurious initramfs rebuild
  Documentation: explain the difference between __bitwise and __bitwise__
  kbuild: make it possible for the linker to discard local symbols from vmlinux
  kbuild: remove pointless strdup() on arguments passed to new_module() in modpost
  kbuild: fix a few typos in top-level Makefile
  kbuild: introduce destination-y for exported headers
  kbuild: use git svn instead of git-svn in setlocalversion
  kconfig: fix update-po-config to accect backslash in input
  kbuild: fix option processing for -I in headerdep
2009-04-13 12:20:01 -07:00
Linus Torvalds
eebb2afb82 Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  ata: fix obviously wrong comment
  ahci: force CAP_NCQ for earlier NV MCPs
  [libata] sata_via: kill uninit'd var warning
2009-04-13 11:46:04 -07:00
Linus Torvalds
b534d388c2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (22 commits)
  Input: i8042 - add HP DV9700 to the noloop list
  Input: arrange drivers/input/misc/Makefile in alphabetical order
  Input: add AD7879 Touchscreen driver
  Input: add AD7877 touchscreen driver
  Input: bf54x-keys - fix typo in warning
  Input: add driver for S1 button of rb532
  Input: generic driver for rotary encoders on GPIOs
  Input: hilkbd - fix crash when removing hilkbd module
  Input: atkbd - add quirk for Fujitsu Siemens Amilo PA 1510
  Input: atkbd - consolidate force release quirk setup
  Input: add accelerated touchscreen support for Marvell Zylonite
  Input: ucb1400_ts, mainstone-wm97xx - add BTN_TOUCH events
  Input: wm97xx - use disable_irq_nosync() for Mainstone
  Input: wm97xx - add BTN_TOUCH event to wm97xx to use it with Android
  Input: fix polling of /proc/bus/input/devices
  Input: psmouse - add newline to OLPC HGPK touchpad debugging
  Input: ati_remote2 - check module params
  Input: ati_remote2 - add per device attrs
  Input: ati_remote2 - complete suspend support
  Input: stop autorepeat timer on key release
  ...
2009-04-13 11:37:23 -07:00
Rafael J. Wysocki
c751085943 PM/Hibernate: Wait for SCSI devices scan to complete during resume
There is a race between resume from hibernation and the asynchronous
scanning of SCSI devices and to prevent it from happening we need to
call scsi_complete_async_scans() during resume from hibernation.

In addition, if the resume from hibernation is userland-driven, it's
better to wait for all device probes in the kernel to complete before
attempting to open the resume device.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-13 11:37:07 -07:00
Linus Torvalds
7b11428d37 Merge git://git.infradead.org/iommu-2.6
* git://git.infradead.org/iommu-2.6:
  intel-iommu: Avoid panic() for DRHD at address zero.
  Intel-IOMMU Alignment Issue in dma_pte_clear_range()
2009-04-13 11:35:50 -07:00
Linus Torvalds
b8256b45d1 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: add linux kernel support for YMM state
  x86: fix wrong section of pat_disable & make it static
  x86: Fix section mismatches in mpparse
  x86: fix set_fixmap to use phys_addr_t
  x86: Document get_user_pages_fast()
  x86, intr-remap: fix eoi for interrupt remapping without x2apic
2009-04-13 11:32:09 -07:00
Linus Torvalds
8255309b88 Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  tracing/filters: return proper error code when writing filter file
  tracing/filters: allow user input integer to be oct or hex
  tracing/filters: fix NULL pointer dereference
  tracing/filters: NIL-terminate user input filter
  ftrace: Output REC->var instead of __entry->var for trace format
  Make __stringify support variable argument macros too
  tracing: fix document references
  tracing: fix splice return too large
  tracing: update file->f_pos when splice(2) it
  tracing: allocate page when needed
  tracing: disable seeking for trace_pipe_raw
2009-04-13 11:31:28 -07:00
Linus Torvalds
bf20753c0c Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  lockdep: continue lock debugging despite some taints
  lockdep: warn about lockdep disabling after kernel taint
2009-04-13 11:30:26 -07:00
Andrew Morton
01599fca67 cpufreq: use smp_call_function_[single|many]() in acpi-cpufreq.c
Atttempting to rid us of the problematic work_on_cpu().  Just use
smp_call_fuction_single() here.

This repairs a 10% sysbench(oltp)+mysql regression which Mike reported,
due to

  commit 6b44003e5c
  Author: Andrew Morton <akpm@linux-foundation.org>
  Date:   Thu Apr 9 09:50:37 2009 -0600

      work_on_cpu(): rewrite it to create a kernel thread on demand

It seems that the kernel calls these acpi-cpufreq functions at a quite
high frequency.

Valdis Kletnieks also reports that this causes 70-90 forks per second on
his hardware.

Cc: Valdis.Kletnieks@vt.edu
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Zhao Yakui <yakui.zhao@intel.com>
Acked-by: Dave Jones <davej@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Mike Galbraith <efault@gmx.de>
Cc: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
[ Made it use smp_call_function_many() instead of looping over cpu's
  with smp_call_function_single()    - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-13 11:09:46 -07:00