IRQ_POLL_F_SCHED
if (test_bit(IRQ_POLL_F_SCHED, &iop->state))
while (test_and_set_bit(IRQ_POLL_F_SCHED, &iop->state))
BUG_ON(!test_bit(IRQ_POLL_F_SCHED, &iop->state));
clear_bit_unlock(IRQ_POLL_F_SCHED, &iop->state);
if (test_and_set_bit(IRQ_POLL_F_SCHED, &iop->state))
clear_bit_unlock(IRQ_POLL_F_SCHED, &iop->state);