perf stat: Better report failure to collect system wide stats
Before:
[acme@doppio linux-2.6-tip]$ perf stat -a sleep 1s
Performance counter stats for 'sleep 1s':
<not counted> task-clock-msecs
<not counted> context-switches
<not counted> CPU-migrations
<not counted> page-faults
<not counted> cycles
<not counted> instructions
<not counted> branches
<not counted> branch-misses
<not counted> cache-references
<not counted> cache-misses
1.016998463 seconds time elapsed
[acme@doppio linux-2.6-tip]$
Now:
[acme@doppio linux-2.6-tip]$ perf stat -a sleep 1s
No permission to collect system-wide stats.
Consider tweaking /proc/sys/kernel/perf_event_paranoid.
[acme@doppio linux-2.6-tip]$
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1269274229-20442-4-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
1 file changed