Em Thu, Aug 08, 2013 at 04:42:33PM -0400, David Ahern escreveu: > On 8/8/13 10:53 AM, Arnaldo Carvalho de Melo wrote: > >Em Wed, Aug 07, 2013 at 10:50:43PM -0400, David Ahern escreveu: > >>Occassionally events (e.g., context-switch, sched tracepoints) are losing > >>the conversion of sample data associated with a thread. For example: > > > >Humm, if we have a tool that traverses the list of threads in a machine > >it will not know, after one of them exits, about it being dead, so I > >think this needs to add a thread->dead, no? > > > >As of now, from what I can remember, the closest to such a tool would > >be: > > > > perf top --sort pid > > > >But that uses hist_entries that would eventually be decayed as samples > >would cease to be taken at most a few moments after the EXIT event. > > > >But at least for debugging purposes, machine__fprintf() would list dead > >threads as being present, i.e. alive till its pid gets reused. > > > >This is the only, minor, problem that I see with this solution, what do > >you think? > > I can add the exit timestamp to the thread struct. non-0 means it > has died. Ok with that as an indicator?
I thought about that, at first looked like overengineering and wasting some bytes, as we don't have an user for that now, all we need is a single bit (or bool) just after ->comm_set :-) If we ever have a use for knowing when the thread exited, no problem in adding it then. - Arnaldo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
