On Tuesday 03 September 2013 15:05:45 Thibault, Daniel wrote: > ---------------------------------------------------------------------- > > Date: Tue, 20 Aug 2013 11:27:46 +0200 > > > > If that is the intention, then it would be better to specify the commands in reverse order: > > > > # lttng enable-event "!ab" -u > > # lttng enable-event "a*" -u > > > > or even better: > > > > # lttng enable-event "!ab" "a*" -u > > > > > However, if the event 'ab' is already registered in the session, the first command would enable the event 'ab'. > > > Should the second command now disable the event 'ab', or should the command only apply to future registrations of events ? > > > > That is exactly what would happen in an *active* *session* if you issue > > the commands in the order you originally suggested. > > Incoming events matching "a*" are recorded up to the point where 'lttng > > enable-event "!ab"' is executed. From then on, 'ab'-events are excluded > > from recording. > > > > Paul Woegerer, SW Development Engineer > ---------------------------------------------------------------------- > > It makes little sense to me that the sequence: > > # lttng enable-event "!ab" -u > # lttng enable-event "a*" -u > > should "enable all events except 'ab'" (the original intent). There would > be no way of ever turning 'ab' back on, unless the command treated the wild
To reenable event 'ab' you would simply invoke: lttng disable-event "!ab" -u This would effectively remove the exclusion and let again any event matching "a*" (like 'ab') in. > I note that the "!" special character was not used in older versions of enable-event, leading to limited backward compatibility of this new interface convention. Is the intent to remove the disable-event command entirely? Not at all. This is orthogonal to enable-event/disable-event. Regarding the "!" ... we are open for suggestions here. We would even prefer to use a character that is rejected by current versions of lttng (i.e. results in an error when used in "lttng enable-event", because this would make checking if the exclusion feature is available much easier). Thanks, Paul -- Paul Woegerer, SW Development Engineer Sourcery Analyzer <http://go.mentor.com/sourceryanalyzer> Mentor Graphics, Embedded Software Division _______________________________________________ lttng-dev mailing list lttng-dev@lists.lttng.org http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
