On Sat, Mar 14, 2015 at 03:14:14PM +0100, Oleg Nesterov wrote: > Again, again, I didn't read this series yet. But the proper solution (afaics) > should move this "autoreap" check in release_task/__ptrace_detach(). If the > task is traced. Debugger should check ->autoreap and skip another > do_notify_parent(). As mentioned in the mail I just sent, I think I can just move the autoreap handling *into* do_notify_parent, and treat it as though the parent had SA_NOCLDWAIT set. > Speaking of autoreap... If ->exit_signal is zero, then the exiting child > doesn't send the notification to its parent, still it doesn't autoreap > itself. To me this looks strange, and in fact it seems to me that this > is only by mistake. I am wondering if we can treat ->exit_signal == 0 > as "autoreap" too. As usual, most probably the answer is "no, because it > is too late to change the historical behaviour". But this is off-topic. Historical behavior, and potentially sensible behavior; you might not want notification, but you might still want to get the child's exit status by calling wait, which means you need the process to stick around as a zombie until you wait on it. That'd be the main advantage of adding a CLONE_AUTOREAP flag: it allows you to get the same autoreaping behavior you'd get if you had SIGCHLD ignored, but without actually sending a signal and without caring how the process-wide signal handling is set up. So you'd pass a 0 signal, and CLONE_AUTOREAP. And then if you *want* the exit notification, you can get it via the file descriptor. - Josh Triplett -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
