[GIT PULL] tracing: make signal tracepoints more useful

[Oleg Nesterov <oleg@redhat.com>]

Hello,

Please pull from

	git://github.com/utrace/linux sigtrace


Another (4th) attempt to push these simple changes, now in the form
of a pull request (yes, github, I still can't restore my korg account).

2/2 looks like a bugfix to me, but 1/2 changes the output from
trace_signal_generate() and removes trace_signal_overflow_fail.
In essence the change is:

	-       TP_printk("sig=%d errno=%d code=%d comm=%s pid=%d",
	+       TP_printk("sig=%d errno=%d code=%d comm=%s pid=%d grp=%d res=%d",

where
	- grp=0/1 means private or shared

	- res is enum {
			TRACE_SIGNAL_DELIVERED,
			TRACE_SIGNAL_IGNORED,
			TRACE_SIGNAL_ALREADY_PENDING,
			TRACE_SIGNAL_OVERFLOW_FAIL,
			TRACE_SIGNAL_LOSE_INFO,
		};

Obviously this is the user visible change. But personally I do
agree with Seiji who requested this feature. Currently
trace_signal_generate() just records the fact that __send_signal()
was called, you can't know whether the signal was actually sent
or not.

Steven Rostedt says:

	Adding more to a tracepoint is never an issue, even without a library to
	parse the data correctly (which we still need in the distros). Thus this
	change should have no issues.



Oleg Nesterov (2):
      tracing: let trace_signal_generate() report more info, kill overflow_fail/lose_info
      tracing: send_sigqueue() needs trace_signal_generate() too

 include/trace/events/signal.h |   85 +++++++++++------------------------------
 kernel/signal.c               |   28 +++++++++----
 2 files changed, 41 insertions(+), 72 deletions(-)