2012/11/27 Gleb Natapov <gleb@xxxxxxxxxx>: > What is the semantics of enter_idle()/exit_idle(), what are they used for? It's used by drivers/idle/i7300_idle.c for some tracking. I don't know much the details. enter_idle() is called right before the CPU is set to lower power mode: hlt() exit_idle() is called anytime we exit this low power mode: irq, polling on need_resched(), etc... > Not present fault happening in idle task does not mean we exit idle > task. If this happens exception handler will execute sti; hlt waiting > for missing page to be ready. Any interrupt happening during this hlt > will do exit_idle() by itself. Well, the code executed by this fault should be considered as an exit from idle mode. Now it's a small piece of code and we hlt() quickly so I guess getting of idle_exit() there wouldn't hurt much. It's buggy for now anyway due to that race where we may not have an opportunity to call back idle_enter() if the fault happens between the idle_enter() in the idle loop and the hlt() in the idle loop. -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
