perf record and intel_cqm/llc_occupancy

[Omar Awile <omar.awile@cern.ch>]

Dear perf users,

I have a question regarding perf’s support for Intel Cache Monitoring Technology. For the event intel_cqm/llc_occupancy, ‘perf stat’ works fine but ‘perf record’ does not. For example when I execute:

> perf record -e intel_cqm/llc_occupancy/ sleep 1

I get  

Error:
The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (intel_cqm/llc_occupancy/).
/bin/dmesg may provide additional information.
No CONFIG_PERF_EVENTS=y kernel support configured?

but when I execute:

> perf stat -e intel_cqm/llc_occupancy/ sleep 1

I get

Performance counter stats for 'sleep 1':

   40,960.00 Bytes intel_cqm/llc_occupancy/
   
   1.001455067 seconds time elapsed


* My perf and kernel version is 4.6.2-1.el7.elrepo.x86_64.
* cat /proc/sys/kernel/perf_event_paranoid returns -1
* The CPU is the E5-2630 v4 2.20GHz “Broadwell”.

Is it possible that for intel_cqm/llc_occupancy interrupts are not supported? In that case it wouldn’t be more appropriate to return ENOTSUP instead of EINVAL?

Thanks a lot in advance,

Omar

--
Omar Awile, Ph.D.
Systems Performance Engineer
CERN - 513/R-046