Re: [BUG] perf stat: events inheritance can break task targets

2014-07-08 Thread Jiri Olsa
On Mon, Jul 07, 2014 at 09:46:35PM +0200, Peter Zijlstra wrote: > On Mon, Jul 07, 2014 at 07:00:40PM +0200, Jiri Olsa wrote: > > diff --git a/kernel/trace/trace_event_perf.c > > b/kernel/trace/trace_event_perf.c > > index 5d12bb4..b44184b 100644 > > --- a/kernel/trace/trace_event_perf.c > > +++ b/

Re: [BUG] perf stat: events inheritance can break task targets

2014-07-07 Thread Peter Zijlstra
On Mon, Jul 07, 2014 at 07:00:40PM +0200, Jiri Olsa wrote: > diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c > index 5d12bb4..b44184b 100644 > --- a/kernel/trace/trace_event_perf.c > +++ b/kernel/trace/trace_event_perf.c > @@ -24,6 +24,9 @@ static int total_ref_count

Re: [BUG] perf stat: events inheritance can break task targets

2014-07-07 Thread Jiri Olsa
On Mon, Jul 07, 2014 at 08:41:57PM +0400, Alexander Yarygin wrote: SNIP > ^C > > When perf is running, every invoke of pthread_create() returns -EPERM. > > On the kernel side, copy_process() creates a task, scheduled it, > than perf_event_init_task() (kernel/events/core.c) returns an error, > a

[BUG] perf stat: events inheritance can break task targets

2014-07-07 Thread Alexander Yarygin
perf stat can block pthread_create() for a multithreaded userspace process (i.e. qemu) when: - process is running with non-root privileges - perf stat is running as root with trace events in -e option - it is attached to the process's pid. Here is a simple test scenario: ~$ cat test.c #include #