Hello, Mike. On Thu, Feb 04, 2016 at 03:00:17AM +0100, Mike Galbraith wrote: > Isn't it the case that, currently at least, each and every spot that > requires execution on a specific CPU yet does not take active measures > to deal with hotplug events is in fact buggy? The timer code clearly > states that the user is responsible, and so do both workqueue.[ch]. Yeah, the usages which require affinity for correctness must flush the work items from a cpu down callback. > I was surprised me to hear that some think they have an iron clad > guarantee, given the null and void clause is prominently displayed. Nobody is (or at least should be) expecting workqueue to handle affinity across CPU offlining events. That is not the problem. The problem is that currently queue_work(work) and queue_work_on(smp_processor_id(), work) are identical and there likely are affinity-for-correctness users which are doing the former. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html