tc_cold_unblock
tc_cold_unblock(tc, fetch_and_zero(&tc->lock_wakeref));
tc_cold_unblock(tc, fetch_and_zero(&tc->lock_wakeref));
tc_cold_unblock(tc, fetch_and_zero(&tc->lock_wakeref));
tc_cold_unblock(tc, fetch_and_zero(&tc->lock_wakeref));
tc_cold_unblock(tc, fetch_and_zero(&tc->lock_wakeref));
tc_cold_unblock(tc, fetch_and_zero(&tc->lock_wakeref));