PERF_STS_LNKUP
test_bit(PERF_STS_LNKUP, &peer->sts) ? "up" : "down");
!test_and_set_bit(PERF_STS_LNKUP, &peer->sts)) {
test_and_clear_bit(PERF_STS_LNKUP, &peer->sts)) {