Em Thu, Nov 12, 2015 at 06:57:28PM -0300, Arnaldo Carvalho de Melo escreveu: > Em Thu, Nov 12, 2015 at 09:07:20PM +0000, Kornievskaia, Olga escreveu:
> > Can somebody tell me if perf can do “timing-of-operation” type of > > measurement? By that I mean, say there are two tracepoints > > “foobar_enter” and “foobar_exit”. Each tracepoint logs a timestamp. > > I’d like to be able to say that on average it takes that many > > time-units between “enter” and “exit” tracepoints. I haven’t been > > able to find something like that with “perf”. > Well, you can do: > > # perf record -a -e sched:*waking*,sched:*wakeup* sleep 2 > [ perf record: Woken up 1 times to write data ] > [ perf record: Captured and wrote 0.199 MB perf.data (156 samples) ] > # perf script -g python > generated Python script: perf-script.py > # grep '^def ' perf-script.py > def trace_begin(): > def trace_end(): > def sched__sched_wakeup_new(event_name, context, common_cpu, > def sched__sched_wakeup(event_name, context, common_cpu, > def sched__sched_waking(event_name, context, common_cpu, > def trace_unhandled(event_name, context, event_fields_dict): > def print_header(event_name, cpu, secs, nsecs, pid, comm): > # > > The prototype for sched__sched_wakeup(), for instance is: > > def sched__sched_wakeup(event_name, context, common_cpu, > common_secs, common_nsecs, common_pid, common_comm, > common_callchain, comm, pid, prio, success, > target_cpu): > > Then do some minimal coding for what you want, because you need > to match it using some key, i.e. same pid is enough for some cases, for > others you need pid + fd, etc. If you do not change that script, then running it will produce: # perf script -s perf-script.p in trace_begin sched__sched_waking 2 09156.170326579 16181 perf comm=perf, pid=16182, prio=120, success=1, target_cpu=3 sched__sched_wakeup 2 09156.170329797 16181 perf comm=perf, pid=16182, prio=120, success=1, target_cpu=3 sched__sched_waking 3 09156.170446653 16182 perf comm=migration/3, pid=28, prio=0, success=1, target_cpu=3 <SNIP> in trace_end - Arnaldo -- To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
