On 03/20, Jens Axboe wrote: > > --- a/kernel/signal.c > +++ b/kernel/signal.c > @@ -2349,6 +2349,10 @@ static bool do_signal_stop(int signr) > > t = current; > while_each_thread(current, t) { > + /* don't STOP PF_IO_WORKER threads */ > + if (t->flags & PF_IO_WORKER) > + continue; > + This is not enough. At least task_join_group_stop() should check PF_IO_WORKER too. Oleg.