On Thu, 9 Feb 2017, Michal Hocko wrote: > Christoph, you are completely ignoring the reality and the code. There > is no need for stop_machine nor it is helping anything. As the matter > of fact there is a synchronization with the cpu hotplug needed if you > want to make a per-cpu specific operations. get_online_cpus is the > most straightforward and heavy weight way to do this synchronization > but not the only one. As the patch [1] describes we do not really need > get_online_cpus in drain_all_pages because we can do _better_. But > this is not in any way a generic thing applicable to other code paths. > > If you disagree then you are free to post patches but hand waving you > are doing here is just wasting everybody's time. So please cut it here > unless you have specific proposals to improve the current situation. I am fine with the particular solution here for this particular problem. My problem is the general way of having to synchronize via get_online_cpus() because of cpu hotplug operations. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
