On Tue, Jan 23, 2018 at 07:02:44AM +0800, Jin, Yao wrote: SNIP
> > > threads = thread_map__new_str(target->pid, target->tid, > > > target->uid, > > > - target->per_thread); > > > + target->per_thread && > > > target->system_wide); > > > > At first glance I thought your solution would do the trick but perf > > record does use target->system_wide when the '-a' switch is used. > > Moreover specifying the '-a' switch doesn't prevent the '--per-thread' > > option from being used as well, making both target->perf_thread and > > target_system_wide equal to true (and that is not good). > > > > Although not a fan of adding more to struct target, the advantage of > > having target->all_threads is that we are guaranteed that it isn't > > used anywhere else. > > > > Let me know what you think, > > Mathieu > > > > If we specify both '-a' and '--per-thread' to perf record, perf record will > override'--per-thread'. So now target->per_thread = false, and > target->system_wide = true. > > If we specify '--per-thread' only to perf record, target->per_thread = true, > and target->system_wide = false. > > So whatever for any case, target->per_thread && target->system_wide is > false. > > Since the parameter is false, in thread_map__new_str(), it will not execute > the thread_map__new_all_cpus(). So that will not change perf record previous > behavior. > > In perf stat, it allows the case that target->per_thread and > target->system_wide are all true. That means we want to collect system-wide > per-thread metrics. could you please put this description into comment before the thread_map__new_str is called? thanks, jirka
