Re: [PATCHv2] perf tools: Force uncore events to system wide monitoring

[Jiri Olsa]

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