I have a question about cond_resched(). What is the condition under which I should invoke cond_resched() irreplaceably?
For example, I see the following code in ksoftirqd(), preempt_enable_no_resched(); cond_resched(); preempt_disable(); But I do not understand why I should not write the following code, preempt_enable(); preempt_disable(); Are the above two pieces of code equal in functionality? On the other hand, I see cond_resched() check and set PREEMPT_ACTIVE. I currently do not understand why it should do this, since I think PREEMPT_ACTIVE is only used to be set in the return-from-interrupt code in order to prevent schedule() from removing task from run queue unpredictably. But for cond_resched(), which is a planned voluntary switch, why does it also deal with this flag? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
