Quoting Ali Saidi <[EMAIL PROTECTED]>: > > On Jun 27, 2008, at 9:16 PM, Rick Strong wrote: > >> >>> >>> On Jun 26, 2008, at 7:01 PM, Rick Strong wrote: >>> >>>> >>>> 1) If using just quiesce (without cycles or ns ... etc), m5sim.org >>>> states that an interrupt is the means of waking up the core. Can any >>>> interrupt be used or must there be a specific one? Also, for an >>>> interrupt to schedule the tick() call after the quiesce call, which >>>> lines of code are actually called after the interrupt is received to >>>> reschedule the tick event? >>> Any interrupt will wake the core. You can think of quiesce as an >>> indication that the CPU has nothing to do. In the case of the Linux >>> kernel the scheduler has called default_idle() on the cpu where it >>> either spins of a tight loop or get put into a lower power state >>> depending on the cpu/architecture. When an interrupt occurs an the >>> IntrControl object processes it and it calls cpu->post_interrupt() >>> the >>> specific CPUs implementation then does the right thing. In the case >>> of >>> a simple CPU if it was suspended it calls thread->activate() which >>> ultimately calls cpu->activateContext() which will reschedule the >>> tick >>> event if it's not scheduled. >>> >>> Ali >> So I wish to add a parameter to O3CPU.py that defines a delay in >> cycles >> from the time a sleeping cpu wakes up and the time that any thread >> can >> start executing on the cpu. So ideally, when >> src/cpu/o3/alpha/cpu_impl.hh:post_interrupt is called from the >> interrupt, I want to pass a delay in cyles to >> this->threadContexts[0]->activate(). Which would be the best class to >> add the quiesceWakeupDelay() so that I can set the delay in python, >> have >> access to the delay value in post_interrupt, an ideally have a >> different >> delay for each cpu. >> >> Also, do I have to pass the delay to wakeCPU() in function >> src/cpu/o3/alpha/cpu_impl.hh:post_interrupt, or can I wake the cpu and >> put the delay in the activation of the thread context? My guess of a >> potential problem is that if I wakeup a cpu but put a delay for the >> thread, then some other thread from another cpu could startup on the >> cpu. > I think you should just be able to replace the activateContex() > function with a function that created a delay. After the event expired > you would then execute the what activateContext() currently does. > However, I'm not an expert at the O3 CPU, so you might have to > experiment a bit. > > Ali >
I agree with what Ali stated. I don't believe it'll be an issue if the CPU starts up and the thread starts up later, but you might as well avoid any potential issues but simple creating another event. You should create the new function in those same source files: src/cpu/o3/alpha/cpu.hh and cpu_impl.hh. Hope this helps. Kevin _______________________________________________ m5-users mailing list [email protected] http://m5sim.org/cgi-bin/mailman/listinfo/m5-users
