On Mon, Sep 8, 2014 at 2:49 PM, Jiri Olsa <[email protected]> wrote: > > On Mon, Sep 08, 2014 at 02:35:06PM +0200, Stephane Eranian wrote: > > Hi, > > > > It seems something is seriously broken with perf_events in > > 3.17-rcX. I have tried rc3, rc4. No way to get any counts > > out using perf stat in per-process mode. I am trying on Intel > > and the PMU is correctly detected: > > > > $ perf stat -e cycles ls > > <not counted> cycles > > > > It is not a permission problem. It is a read problem! > > $ strace perf stat -e cycles ls > > > > perf_event_open(0x27d7e20, 2261, -1, -1, 0x8 /* PERF_FLAG_??? */) = 3 > > write(6, "\0", 1) = 1 > > close(6) = 0 > > wait4(-1, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0, NULL) = 2261 > > --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=2261, > > si_status=0, si_utime=0, si_stime=0} --- > > rt_sigreturn() = 2261 > > read(3, "", 24) = 0 > > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > ouch thats me.. sry :-\ > > the PERF_EVENT_STATE_EXIT check should not go to the > read path.. could you please test attached patch? > > jirka > Works for me again now. Thanks for the quick fix. Please push it upstream.
Acked-by: Stephane Eranian <[email protected]> > > > --- > diff --git a/kernel/events/core.c b/kernel/events/core.c > index d8cb4d2..6d1c9ce 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -3600,8 +3600,7 @@ perf_read_hw(struct perf_event *event, char __user > *buf, size_t count) > * error state (i.e. because it was pinned but it couldn't be > * scheduled on to the CPU at some point). > */ > - if ((event->state == PERF_EVENT_STATE_ERROR) || > - (event->state == PERF_EVENT_STATE_EXIT)) > + if (event->state == PERF_EVENT_STATE_ERROR) > return 0; > > if (count < event->read_size) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
