On 10/01, Michal Hocko wrote: > > On Wed 30-09-15 20:24:05, Oleg Nesterov wrote: > [...] > > It is possible that the group leader > > has the pending SIGKILL because its sub-thread originated the coredump, > > in this case we must not skip this process. > > I do not understand this. If the group leader has SIGKILL pending it > will die anyway regardless whether we send another sigkill or not, no?
Yes it will die, but only after the coredump is finished. Suppose we have a thread group with the group leader P and another thread T. If T starts the coredump, it sends SIGKILL to P and waits until it parks in exit_mm(). Then T actually dumps the core which may need more memory, a lot of time, etc. We need to kill this process. Yes, P is already killed and it sleeps in TASK_UNINTERRUPTIBLE so this thread does not need SIGKILL. But do_send_sig_info(P) will also find T and kill it too to make dump_interrupted() == T. 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/
