hwcache events and kernel/userspace event modifiers - bug?

hwcache events and kernel/userspace event modifiers - bug?

[Michael Petlan]

Hi,

when using the "k" and "u" event modifiers in order to exclude
kernel or userspace counting, the "hw" events print the modifier
along with the event names in results. When doing the same with
a "hwcache" event, the report shows events without modifiers.

$ perf stat -e cycles:u -e L1-dcache-loads:u -- true

  Performance counter stats for 'true':

            153,771      cycles:u
             24,457      L1-dcache-loads

        0.001813975 seconds time elapsed

While "cycles:u" has the ":u" modifier, "L1-dcache-loads" does
not. Despite that, the kernel/userspace excluding seem to work:

$ perf stat -e L1-dcache-loads:u -e L1-dcache-loads:k -e L1-dcache-loads:ku -- ls

  Performance counter stats for 'ls':

            146,714      L1-dcache-loads
            305,080      L1-dcache-loads
            451,794      L1-dcache-loads

        0.002221714 seconds time elapsed

Where 146714 + 305080 = 451794, so k+u is equal to ku.

This happens with the Arnaldo's latest perf/core perf, the same
as with the others.

Might that be a bug?
Thanks.

Michael