Hello, Frederic. On Fri, Dec 02, 2011 at 05:28:03PM +0100, Frederic Weisbecker wrote: > But I don't think it's very useful to protect against irq_exit_thread(), > what happens there is purely of internal irq interest. > > Then right after, PF_EXITING is set before any interesting change. > Isn't it possible to simply lock this flag setting? IIRC, as soon > as the PF_EXITING flag is set, you ignore the task for attachment. I think that's technically possible but it does introduce another class of tasks - the dying ones. e.g. If a task has PF_EXITING set and the containing process is migrating, we'll have to migrate all tasks but the dying one and cgroup ->exit callbacks can be called on the lonely task after the migration is complete. It's kinda messy and if someone makes a wrong assumption there, the bug is gonna be even more difficult to reproduce / track down than now. Yes, smaller scope locking is nicer but I would like to avoid api weirdities like that. Thanks. -- tejun _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/linux-pm
