On Wed, Mar 01, 2017 at 06:36:39PM -0300, Arnaldo Carvalho de Melo wrote: SNIP
> [acme@jouet linux]$ perf stat usleep 1 > > Performance counter stats for 'usleep 1': > > 2.022049 task-clock:u (msec) # 0.181 CPUs utilized > > 0 context-switches:u # 0.000 K/sec > > 0 cpu-migrations:u # 0.000 K/sec > > 48 page-faults:u # 0.024 M/sec > > 2,177,301 cycles:u # 1.077 GHz > > 245,106 instructions:u # 0.11 insn per cycle > > 48,000 branches:u # 23.738 M/sec > > 3,936 branch-misses:u # 8.20% of all branches > > > 0.011181563 seconds time elapsed > > [acme@jouet linux]$ > > --------------------------------------------- > > Seems related to the auto :u done when the user can't do kernel profiling, > etc. > > Re-applying your patch, to triple check: > > [acme@jouet linux]$ perf stat usleep 1 2>&1 | head -2 > Error: > You may not have permission to collect system-wide stats. > [acme@jouet linux]$ > > ------------------------------------------------ > > Waiting for v3 :-) oh my... I'll check thanks, jirka
