A long preemptive inhabitation in ordinal Linux degrades real-time response time. An interrupt latency is allowed to be between several tens of msecs in PCs and servers. On the other hands, in mobile phones, an interrupt latency is required to be between several p secs and several hundreds of p secs.
Solution candidate: An external interrupt arrives at CPU and the corresponding device drivers and process preemption occurs.
Until the process preemption, the following steps are required