On 08/17, Oleg Nesterov wrote: > > On 08/16, Peter Zijlstra wrote: > > > > write_lock_irq(&tasklist_lock) > > task_lock(parent) parent->alloc_lock > > And this is already wrong. See the comment above task_lock(). > > > And since it_lock is IRQ-safe and alloc_lock isn't, you've got the IRQ > > inversion deadlock reported. > > Yes. Or, IOW, write_lock(tasklist) is IRQ-safe and thus it can't nest > with alloc_lock. > > > David, Al, anybody want to have a go at fixing this? > > I still think that task_work_add() should synhronize with exit_task_work() > itself and fail if necessary. But I wasn't able to convince Al ;)
And this is my old patch: http://marc.info/?l=linux-kernel&m=134082268721700 It should be re-diffed of course. Oleg. -- 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/
