Re: [PATCH v3] perf stat: Show percore counts in per CPU output

[Ravi Bangoria]

Hi Jin,

On 2/13/20 12:45 PM, Jin Yao wrote:
> With this patch, for example,
>
>   # perf stat -e cpu/event=cpu-cycles,percore/ -a -A --percore-show-thread  -- sleep 1
>
>    Performance counter stats for 'system wide':
>
>   CPU0               2,453,061      cpu/event=cpu-cycles,percore/
>   CPU1               1,823,921      cpu/event=cpu-cycles,percore/
>   CPU2               1,383,166      cpu/event=cpu-cycles,percore/
>   CPU3               1,102,652      cpu/event=cpu-cycles,percore/
>   CPU4               2,453,061      cpu/event=cpu-cycles,percore/
>   CPU5               1,823,921      cpu/event=cpu-cycles,percore/
>   CPU6               1,383,166      cpu/event=cpu-cycles,percore/
>   CPU7               1,102,652      cpu/event=cpu-cycles,percore/
>
> We can see counts are duplicated in CPU pairs
> (CPU0/CPU4, CPU1/CPU5, CPU2/CPU6, CPU3/CPU7).

I was trying this patch and I am getting bit weird results when any cpu
is offline. Ex,

  $ lscpu | grep list
  On-line CPU(s) list:             0-4,6,7
  Off-line CPU(s) list:            5

  $ sudo ./perf stat -e cpu/event=cpu-cycles,percore/ -a -A --percore-show-thread -vv -- sleep 1
    ...
  cpu/event=cpu-cycles,percore/: 0: 23746491 1001189836 1001189836
  cpu/event=cpu-cycles,percore/: 1: 19802666 1001291299 1001291299
  cpu/event=cpu-cycles,percore/: 2: 24211983 1001394318 1001394318
  cpu/event=cpu-cycles,percore/: 3: 54051396 1001516816 1001516816
  cpu/event=cpu-cycles,percore/: 4: 6378825 1001064048 1001064048
  cpu/event=cpu-cycles,percore/: 5: 21299840 1001166297 1001166297
  cpu/event=cpu-cycles,percore/: 6: 13075410 1001274535 1001274535
  
   Performance counter stats for 'system wide':
  
  CPU0              30,125,316      cpu/event=cpu-cycles,percore/
  CPU1              19,802,666      cpu/event=cpu-cycles,percore/
  CPU2              45,511,823      cpu/event=cpu-cycles,percore/
  CPU3              67,126,806      cpu/event=cpu-cycles,percore/
  CPU4              30,125,316      cpu/event=cpu-cycles,percore/
  CPU7              67,126,806      cpu/event=cpu-cycles,percore/
  CPU0              30,125,316      cpu/event=cpu-cycles,percore/
  
         1.001918764 seconds time elapsed

I see proper result without --percore-show-thread:

  $ sudo ./perf stat -e cpu/event=cpu-cycles,percore/ -a -A -vv -- sleep 1
    ...
  cpu/event=cpu-cycles,percore/: 0: 11676414 1001190709 1001190709
  cpu/event=cpu-cycles,percore/: 1: 39119617 1001291459 1001291459
  cpu/event=cpu-cycles,percore/: 2: 41821512 1001391158 1001391158
  cpu/event=cpu-cycles,percore/: 3: 46853730 1001492799 1001492799
  cpu/event=cpu-cycles,percore/: 4: 14448274 1001095948 1001095948
  cpu/event=cpu-cycles,percore/: 5: 42238217 1001191187 1001191187
  cpu/event=cpu-cycles,percore/: 6: 33129641 1001292072 1001292072
  
   Performance counter stats for 'system wide':
  
  S0-D0-C0             26,124,688      cpu/event=cpu-cycles,percore/
  S0-D0-C1             39,119,617      cpu/event=cpu-cycles,percore/
  S0-D0-C2             84,059,729      cpu/event=cpu-cycles,percore/
  S0-D0-C3             79,983,371      cpu/event=cpu-cycles,percore/
  
         1.001961563 seconds time elapsed

[...]

> +--percore-show-thread::
> +The event modifier "percore" has supported to sum up the event counts
> +for all hardware threads in a core and show the counts per core.
> +
> +This option with event modifier "percore" enabled also sums up the event
> +counts for all hardware threads in a core but show the sum counts per
> +hardware thread. This is essentially a replacement for the any bit and
> +convenient for posting process.

s/posting process/post processing/ ? :)

Ravi