Messages in this thread | | | From | Vince Weaver <> | Date | Wed, 24 Feb 2016 11:42:06 -0500 (EST) | Subject | perf rapl/powercap : powercap has more lenient permissions |
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Hello
so perf_event requires paranoid value of 0 to read the RAPL counters
perf stat -a -e power/energy-cores/ /bin/ls Error: You may not have permission to collect system-wide stats.
But I can use the new powercap driver to read the same values no problem:
cat /sys/devices/virtual/powercap/intel-rapl/intel-rapl:0/intel-rapl:0:0/energy_uj 121384969344
Is this expected? Should the powercap permissions be locked down more?
Just hitting this, as PAPI has at least 4 different interfaces to read the RAPL power values (perf_event, /dev/msr, libmsr, powercap). Five if you count that AMD exports their equivelent info via the hwmon interface.
Vince
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