Messages in this thread | | | Date | Tue, 2 Dec 2014 19:23:51 +0100 | From | Michal Hocko <> | Subject | Re: [PATCH 2/2] oom: kill the insufficient and no longer needed PT_TRACE_EXIT check |
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On Tue 02-12-14 19:05:29, Oleg Nesterov wrote: > On 12/02, Michal Hocko wrote: > > > > On Fri 28-11-14 00:04:08, Oleg Nesterov wrote: > > > After the previous patch we can remove the PT_TRACE_EXIT check in > > > oom_scan_process_thread(), it was added to handle the case when the > > > coredumping was "frozen" by ptrace, but it doesn't really work. If > > > nothing else, we would need to check all threads which could share > > > the same ->mm to make it more or less correct. > > > > > > Signed-off-by: Oleg Nesterov <oleg@redhat.com> > > > > I still do not see why we do not need task->ptrace & PT_TRACE_EXIT check > > here. I do understand that the check on group_leader doesn't make much > > sense. ptrace_event would block until the tracer let the task run again > > which may be never AFAICS. > > No, note that PT_TRACE_EXIT (the last ptrace event) is reported before > PF_EXITING is set.
OK, I managed to confuse myself by the PF_EXITING test before exit_signals in do_exit but now that I am looking closer it seems that this is not interesting from the OOM POV.
Thanks for the clarification. This code is so subtle that I rather ask than miss something.
Acked-by: Michal Hocko <mhocko@suse.cz>
> (just in case... we do have some problems with SIGKILL && ptrace, but > this is completely off-topic and has nothing to do with oom-kill.c) > > Oleg. >
-- Michal Hocko SUSE Labs
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