Lets say we have two queues: priority 1 with Round Robin and priority 2 with Shortest Remaining Time First.

At time 0, process A with a 10 units CPU burst is in SRTF queue. It starts excecuting, and at time 2, process B with 12 units CPU burst arrives at RR queue.

When process B arrives at RR, it is a higher priority process than the currently executing process A. Does the scheduler let process A run its remaining burst, or does it preempt it to run process B?

Silberchaltz's Operating Systems Concepts states that "A process that arrives in queue 1 will preempt a process in queue 2" but I don't clearly understand if it means it can preempt a process in the middle of execution or only if it's sitting in the queue.