linux.git/kernel/trace/trace_events.c, branch v3.4-rc4

ftrace, perf: Add add/del tracepoint perf registration actions

2012-02-21T16:08:25+00:00

Adding TRACE_REG_PERF_ADD and TRACE_REG_PERF_DEL to handle
perf event schedule in/out actions.

The add action is invoked for when the perf event is scheduled in,
while the del action is invoked when the event is scheduled out.

Link: http://lkml.kernel.org/r/1329317514-8131-4-git-send-email-jolsa@redhat.com

Acked-by: Frederic Weisbecker 
Signed-off-by: Jiri Olsa 
Signed-off-by: Steven Rostedt

ftrace, perf: Add open/close tracepoint perf registration actions

2012-02-21T16:08:24+00:00

Adding TRACE_REG_PERF_OPEN and TRACE_REG_PERF_CLOSE to differentiate
register/unregister from open/close actions.

The register/unregister actions are invoked for the first/last
tracepoint user when opening/closing the event.

The open/close actions are invoked for each tracepoint user when
opening/closing the event.

Link: http://lkml.kernel.org/r/1329317514-8131-3-git-send-email-jolsa@redhat.com

Acked-by: Frederic Weisbecker 
Signed-off-by: Jiri Olsa 
Signed-off-by: Steven Rostedt

tracing: fix event_subsystem ref counting

2011-12-05T18:28:44+00:00

Fix a bug introduced by e9dbfae5, which prevents event_subsystem from
ever being released.

Ref_count was added to keep track of subsystem users, not for counting
events.  Subsystem is created with ref_count = 1, so there is no need to
increment it for every event, we have nr_events for that.  Fix this by
touching ref_count only when we actually have a new user -
subsystem_open().

Cc: stable@vger.kernel.org
Signed-off-by: Ilya Dryomov 
Link: http://lkml.kernel.org/r/1320052062-7846-1-git-send-email-idryomov@gmail.com
Signed-off-by: Steven Rostedt

Merge branch 'perf/urgent' into perf/core

2011-07-21T07:29:21+00:00

Merge reason: pick up the latest fixes - they won't make v3.0.

Signed-off-by: Ingo Molnar

tracing: Have "enable" file use refcounts like the "filter" file

2011-07-07T15:22:29+00:00

The "enable" file for the event system can be removed when a module
is unloaded and the event system only has events from that module.
As the event system nr_events count goes to zero, it may be freed
if its ref_count is also set to zero.

Like the "filter" file, the "enable" file may be opened by a task and
referenced later, after a module has been unloaded and the events for
that event system have been removed.

Although the "filter" file referenced the event system structure,
the "enable" file only references a pointer to the event system
name. Since the name is freed when the event system is removed,
it is possible that an access to the "enable" file may reference
a freed pointer.

Update the "enable" file to use the subsystem_open() routine that
the "filter" file uses, to keep a reference to the event system
structure while the "enable" file is opened.

Cc: 
Reported-by: Johannes Berg 
Signed-off-by: Steven Rostedt

tracing: Fix bug when reading system filters on module removal

2011-07-07T15:19:18+00:00

The event system is freed when its nr_events is set to zero. This happens
when a module created an event system and then later the module is
removed. Modules may share systems, so the system is allocated when
it is created and freed when the modules are unloaded and all the
events under the system are removed (nr_events set to zero).

The problem arises when a task opened the "filter" file for the
system. If the module is unloaded and it removed the last event for
that system, the system structure is freed. If the task that opened
the filter file accesses the "filter" file after the system has
been freed, the system will access an invalid pointer.

By adding a ref_count, and using it to keep track of what
is using the event system, we can free it after all users
are finished with the event system.

Cc: 
Reported-by: Johannes Berg 
Signed-off-by: Steven Rostedt

tracing: Convert to kstrtoul_from_user

2011-06-15T02:48:50+00:00

This patch replaces the code for getting an unsigned long from a
userspace buffer by a simple call to kstroul_from_user.
This makes it easier to read and less error prone.

Signed-off-by: Peter Huewe 
Link: http://lkml.kernel.org/r/1307476707-14762-1-git-send-email-peterhuewe@gmx.de
Signed-off-by: Steven Rostedt

tracing: Have event with function tracer check error return

2011-05-26T02:13:39+00:00

The self tests for event tracer does not check if the function
tracing was successfully activated. It needs to before it continues
the tests, otherwise the wrong errors may be reported.

Signed-off-by: Steven Rostedt

Regression: partial revert "tracing: Remove lock_depth from event entry"

2011-05-06T20:20:59+00:00

This partially reverts commit e6e1e2593592a8f6f6380496655d8c6f67431266.

That commit changed the structure layout of the trace structure, which
in turn broke PowerTOP (1.9x generation) quite badly.

I appreciate not wanting to expose the variable in question, and
PowerTOP was not using it, so I've replaced the variable with just a
padding field - that way if in the future a new field is needed it can
just use this padding field.

Signed-off-by: Arjan van de Ven 
Signed-off-by: Linus Torvalds

tracing: Export trace_set_clr_event()

2011-03-10T15:34:51+00:00

Trace events belonging to a module only exists when the module is
loaded. Well, we can use trace_set_clr_event funtion to enable some
trace event at the module init routine, so that we will not miss
something while loading then module.

So, Export the trace_set_clr_event function so that module can use it.

Signed-off-by: Yuanhan Liu 
LKML-Reference: <1289196312-25323-1-git-send-email-yuanhan.liu@linux.intel.com>
Cc: Steven Rostedt 
Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Signed-off-by: Steven Rostedt