On Mon, Sep 12, 2016 at 03:05:38PM +0200, Oleg Nesterov wrote: > But this leads to the question which I wanted to ask many times. > > Why cond_resched() is not NOP if CONFIG_PREEMPT=y ?
Dunno, nobody bothered to do it? We should keep the might_sleep() of course, but the preemption check is pointless. > Perhaps we have some users like, just for example, > > preempt_enable_no_resched(); > cond_resched(); > > which actually want the should_resched() check even if CONFIG_PREEMPT, > but most callers do not? I would hope not, the few preempt_enable_no_resched() users _should_ have an actual schedule() call in the _very_ near future.
