linux-toradex.git/samples/trace_events, branch v4.4.106

Fix tracing sample code warning.

2017-11-08T09:06:28+00:00

commit a0cb2b5c390151837b08e5f7bca4a6ecddbcd39c upstream.

Commit 6575257c60e1 ("tracing/samples: Fix creation and deletion of
simple_thread_fn creation") introduced a new warning due to using a
boolean as a counter.

Just make it "int".

Fixes: 6575257c60e1 ("tracing/samples: Fix creation and deletion of simple_thread_fn creation")
Cc: Steven Rostedt 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

tracing/samples: Fix creation and deletion of simple_thread_fn creation

2017-11-08T09:06:28+00:00

commit 6575257c60e1a26a5319ccf2b5ce5b6449001017 upstream.

Commit 7496946a8 ("tracing: Add samples of DECLARE_EVENT_CLASS() and
DEFINE_EVENT()") added template examples for all the events. It created a
DEFINE_EVENT_FN() example which reused the foo_bar_reg and foo_bar_unreg
functions.

Enabling both the TRACE_EVENT_FN() and DEFINE_EVENT_FN() example trace
events caused the foo_bar_reg to be called twice, creating the test thread
twice. The foo_bar_unreg would remove it only once, even if it was called
multiple times, leaving a thread existing when the module is unloaded,
causing an oops.

Add a ref count and allow foo_bar_reg() and foo_bar_unreg() be called by
multiple trace events.

Fixes: 7496946a8 ("tracing: Add samples of DECLARE_EVENT_CLASS() and DEFINE_EVENT()")
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Greg Kroah-Hartman

Sample: Trace_event: Correct the comments

2015-11-02T19:09:15+00:00

The commit 889204278ccf ("tracing: Update trace-event-sample with
TRACE_SYSTEM_VAR documentation") changed TRACE_SYSTEM to 'sample-trace',
but didn't make the according change of its name in the comments.

Link: http://lkml.kernel.org/r/1443599650-23680-1-git-send-email-zhang.chunyan@linaro.org

Signed-off-by: Chunyan Zhang 
Signed-off-by: Steven Rostedt

tracing: Fix sample output of dynamic arrays

2015-07-17T18:15:13+00:00

He Kuang noticed that the trace event samples for arrays was broken:

"The output result of trace_foo_bar event in traceevent samples is
 wrong. This problem can be reproduced as following:

  (Build kernel with SAMPLE_TRACE_EVENTS=m)

  $ insmod trace-events-sample.ko

  $ echo 1 > /sys/kernel/debug/tracing/events/sample-trace/foo_bar/enable

  $ cat /sys/kernel/debug/tracing/trace

  event-sample-980 [000] ....  43.649559: foo_bar: foo hello 21 0x15
  BIT1|BIT3|0x10 {0x1,0x6f6f6e53,0xff007970,0xffffffff} Snoopy
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                 The array length is not right, should be {0x1}.
  (ffffffff,ffffffff)

  event-sample-980 [000] ....  44.653827: foo_bar: foo hello 22 0x16
  BIT2|BIT3|0x10
  {0x1,0x2,0x646e6147,0x666c61,0xffffffff,0xffffffff,0x750aeffe,0x7}
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                 The array length is not right, should be {0x1,0x2}.
  Gandalf (ffffffff,ffffffff)"

This was caused by an update to have __print_array()'s second parameter
be the count of items in the array and not the size of the array.

As there is already users of __print_array(), it can not change. But
the sample code can and we can also improve on the documentation about
__print_array() and __get_dynamic_array_len().

Link: http://lkml.kernel.org/r/1436839171-31527-2-git-send-email-hekuang@huawei.com

Fixes: ac01ce1410fc2 ("tracing: Make ftrace_print_array_seq compute buf_len")
Reported-by: He Kuang 
Signed-off-by: Steven Rostedt

tracing/samples: Update the trace-event-sample.h with TRACE_DEFINE_ENUM()

2015-04-08T13:39:58+00:00

Document the use of TRACE_DEFINE_ENUM() by adding enums to the
trace-event-sample.h and using this macro to convert them in the format
files.

Also update the comments and sho the use of __print_symbolic() and
__print_flags() as well as adding comments abount __print_array().

Link: http://lkml.kernel.org/r/20150403013802.220157513@goodmis.org

Reviewed-by: Masami Hiramatsu 
Tested-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt

tracing: Update trace-event-sample with TRACE_SYSTEM_VAR documentation

2015-04-08T13:39:55+00:00

Add documentation about TRACE_SYSTEM needing to be alpha-numeric or with
underscores, and that if it is not, then the use of TRACE_SYSTEM_VAR is
required to make something that is.

An example of this is shown in samples/trace_events/trace-events-sample.h

Link: http://lkml.kernel.org/r/20150403013802.220157513@goodmis.org

Reviewed-by: Masami Hiramatsu 
Tested-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt

tracing: Add samples of DECLARE_EVENT_CLASS() and DEFINE_EVENT()

2015-02-09T23:05:51+00:00

Add to samples/trace_events/ the macros DECLARE_EVENT_CLASS() and
DEFINE_EVENT() and recommend using them over multiple TRACE_EVENT()
macros if the multiple events have the same format.

Signed-off-by: Steven Rostedt

tracing: Add TRACE_EVENT_FN example

2015-02-09T23:05:39+00:00

If a function should be called before a tracepoint is enabled
and/or after it is disabled, the TRACE_EVENT_FN() serves this
purpose. But it is not well documented. Having it as a sample would
help developers to know how to use it.

Signed-off-by: Steven Rostedt

tracing: Add TRACE_EVENT_CONDITION sample

2015-02-09T21:05:55+00:00

The sample code lacks an example of TRACE_EVENT_CONDITION, and it
has been expressed to me that this feature for TRACE_EVENT is not
well known and not used when it could be.

Signed-off-by: Steven Rostedt

tracing: Update the TRACE_EVENT fields available in the sample code

2015-02-09T20:27:04+00:00

The sample code in samples/trace_events/ is extremely out of date and does
not show all the new fields that have been added since the sample code
was written. As most people are unaware of these new fields, adding sample
code and explanations of those fields should help out.

Signed-off-by: Steven Rostedt