On Mon, Oct 24, 2016 at 01:29:45PM +0200, Peter Zijlstra wrote: > On Mon, Oct 24, 2016 at 01:27:32PM +0200, Peter Zijlstra wrote: > > On Mon, Oct 24, 2016 at 01:15:27PM +0200, Oleg Nesterov wrote: > > > How about the trivial fix below? > > > > > > Oleg. > > > > > > --- x/kernel/events/core.c > > > +++ x/kernel/events/core.c > > > @@ -1257,7 +1257,7 @@ static u32 perf_event_pid(struct perf_ev > > > if (event->parent) > > > event = event->parent; > > > > > > - return task_tgid_nr_ns(p, event->ns); > > > + return pid_alive(p) ? task_tgid_nr_ns(p, event->ns) : 0; > > > } > > > > Also, now we get a (few) sample(s) with a different pid:tid than prior > > samples and not matching the sched_switch() events. > > > > I can imagine that being somewhat confusing for people/tools. > > > > Acme/Jolsa, any idea if that will bugger perf-report? > > Hurm, then again, I imagine that after unhash_process the PID/TID could > be instantly re-used and then we're still confused.
sounds bad.. I haven't checked the related pid_alive code, but shouldn't we already get the EXIT event in this case? jirka
