atomic_dec_return_relaxed
if (atomic_dec_return_relaxed(&nb_active_threads) == 0)
WARN_ON(atomic_dec_return_relaxed(&d->ref) < 0);
WARN_ON(atomic_dec_return_relaxed(&hist->count[old_idx]) < 0);
int v = atomic_dec_return_relaxed(&net->ct.labels_used);
return atomic_dec_return_relaxed(v);