Re: [GIT PULL] tracing: make signal tracepoints more useful

[Oleg Nesterov <oleg@redhat.com>]

On 01/13, Oleg Nesterov wrote:
>
> Hello,

ping ;)

> 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(-)