Em Fri, Apr 27, 2012 at 09:16:18AM +0900, Namhyung Kim escreveu:Hi,
On Thu, 26 Apr 2012 15:22:55 -0600, David Ahern wrote:On 4/26/12 3:12 PM, Namhyung Kim wrote:Hmm.. No, I can reproduce it without any of this series. And now I think
that it is not related to the number of cpus. On my 4 core (no
hyperthreading) machine at home, the result was same.
BTW, did you change sysctl settings?
$ cat /sys/devices/system/cpu/online
0-3
$ grep . /proc/sys/kernel/perf_event_*
/proc/sys/kernel/perf_event_max_sample_rate:100000
/proc/sys/kernel/perf_event_mlock_kb:516
/proc/sys/kernel/perf_event_paranoid:1
$ grep . /proc/sys/kernel/perf_event_*
/proc/sys/kernel/perf_event_max_sample_rate:100000
/proc/sys/kernel/perf_event_mlock_kb:516
/proc/sys/kernel/perf_event_paranoid:-1
That last one is the key. I have it set to not paranoid and usually
run perf a non-root user.
That's exactly what I want to see :). On perf_mmap() we have:
if ((locked> lock_limit)&& perf_paranoid_tracepoint_raw()&&
!capable(CAP_IPC_LOCK)) {
ret = -EPERM;
goto unlock;
}
So as long as you set perf_event_paranoid to -1 or run perf test as
root, you cannot see the failure.
Ok, after this discussion, David, can I have your acked-by or tested-by?
- Arnaldo