A meaningful metric for stall cycles - likwid-perfctr

[Spakho]

Hi all,

I am working with K10 machines.  likwid-perfctr -g CPI gives me the following metrics:

1) INSTRUCTIONS_RETIRED STAT (Sample value: 2.06153e+12)
2) CPU_CLOCKS_UNHALTED STAT (Sample value: 2.90543e+12)
3) UOPS_RETIRED STAT (Sample value: 2.41861e+12)
4) Runtime [s] STAT ( Sample value:1452.8)
5) CPI STAT( Sample value:22.5519)
6) CPI (based on uops) STAT (Sample value:19.223)
7) IPC STAT (Sample value:11.3526)

I am looking for a meaningful metric for stall cycles.

Do I need to consider CPU_CLOCKS_UNHALTED STAT - UOPS_RETIRED STAT or  CPU_CLOCKS_UNHALTED STAT - INSTRUCTIONS_RETIRED STAT?

Thanks.