Hello, Peter. On Tue, May 05, 2015 at 09:00:57PM +0200, Peter Zijlstra wrote: > On Tue, May 05, 2015 at 12:31:12PM -0400, Tejun Heo wrote: > > What I don't want to happen is controllers failing migrations > > willy-nilly for random reasons leaving users baffled, which we've > > actually been doing unfortunately. Maybe we need to deal with this > > fixed resource arbitration as a separate class and allow them to fail > > migration w/ -EBUSY. > > Ah, _that_ was the problem. > > Which is something created by this co-mounting of controllers. Yeah, partly, but also that it's an extra failure mode which isn't necessary for most controllers. > You could of course store the ss-id of the failing operation in > task_struct and have a file reporting the name of the ss-id. > > That way, there is a simple way to find out which controller failed the > migrate. Given that the resources which can fail are very limited, I don't think we need that right now as long as we limit and document the possible failure cases clearly. Hopefully, this won't devolve into collection of arbitrary failures. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html