Hi! > > > Actually, what do you think about this patch? It removes special > > > handling of TASK_TRACED, and should do the trick, too... > > > > I was surprised, but the patch seems to work okay. Can you replace > > your 1/2 with this one, and see what breaks? > > I don't think anything will _visibly_ break, because (1) even if the traced > task has TIF_SIGPENDING set unnecessarily, it will just notice there is no > real signal to handle and continue and We are generating spurious wakeups, but as you noticed, that should be okay. >(2) the race between the delivery of > the continuation signal and the freezer is damn hard to trigger (still I think > I can wirte some artificial code that would trigger this, although it would > involve a kernel thread sending SIGCONT to a user space process - provided > it's permissible ;-)). It is not really permissible, but I do not see how it would hurt... With that patch, we put TASK_STOPPED tasks into refrigerator, along with everyone else. SIGCONT is *not* going to help them out of refrigerator. We also ignore TASK_STOPPED now, so we'll not proceed until all stopped tasks are in refrigerator. Now... I'm not 100% sure I got the ptrace() cases right (and did not test that)... but TASK_STOPPED cases look pretty trivial to me now. Pavel -- Thanks for all the (sleeping) penguins.
