pf: Convert pfi_kkif to use counter_u64

[kp]

Summary

Improve caching behaviour by using counter_u64 rather than variables
shared between cores. Expect a minor performance improvement.

MFC after: 2 weeks
Sponsored by: Orange Business Services

[philip]

Looks good, modulo minor initialisation nit/remark.

sys/netpfil/pf/pf_if.c

226–245

Is there a point in M_ZEROing? As far as I can tell, everything is explicitly initialised later. Or you could pf_kkif_zero() to make it even clearer.

[kp]

sys/netpfil/pf/pf_if.c

226–245

Paranoia for one, but also because otherwise we can't tell which of the counter allocations have failed and can't safely free in pfi_kkif_free().

Happily this is not in the data path, so we don't actually do this very often. A little bit of extra memory writing here isn't going to hurt anything,

[philip]

Works for me! Thanks for clarifying.