Messages in this thread | | | Date | Thu, 1 Oct 2015 17:27:39 +0200 | From | Michal Hocko <> | Subject | Re: [PATCH -mm v2 1/3] mm/oom_kill: remove the wrong fatal_signal_pending() check in oom_kill_process() |
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On Thu 01-10-15 17:00:10, Oleg Nesterov wrote: > 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.
I am still utterly confused :( Where do we kill T if it is not in the same thread group with P? -- Michal Hocko SUSE Labs
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