cond_resched() checks and conditionally sets PREEMPT_ACTIVE flag for
the current task. The comments says,
/*
* The BKS might be reacquired before we have dropped
* PREEMPT_ACTIVE, which could trigger a second
* cond_resched() call.
*/
My understanding is that cond_resched() would be indirectly invoked
twice recursively, through the following path,
cond_resched() -> schedule() -> reacquire_kernel_lock() -> down() ->
might_sleep() -> might_resched() -> cond_resched().
However, the above path is possible only in a voluntary-preemptive
kernel. In a full-preemptive kernel, I do not find any possible path
to cause recursive cond_resched(). Does that mean we can actually
remove the check and setting of PREEMPT_ACTIVE for a full-preemptive
kernel?
-
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/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
