On Tue, Oct 07, 2014 at 09:50:46PM +0200, Oleg Nesterov wrote: > And note that another caller of task_preempt_count(), set_cpu(), is > fine but it doesn't really need this helper. > > And afaics we do not need ->saved_preempt_count at all, the trivial > patch below makes it unnecessary, we can kill it and all its users. > > Not only this will simplify the code, this will make (well, almost) > the per-cpu preempt counter arch-agnostic. > > Or I missed something?
Two things, per-cpu isn't always faster on some archs, and load-store archs have problems with PREEMPT_NEED_RESCHED, although arguably you can do per-cpu preempt count without that. > Do you think this makes sense? If yes, I'll try to make the patches. It penalizes everything but x86 I think. There is no other arch that has per-cpu preempt count atm. -- 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/
