Re: [PATCH -mm 1/3] mm/oom_kill: remove the wrong fatal_signal_pending()

From: Oleg Nesterov
Date: Wed Sep 30 2015 - 09:47:43 EST


On 09/29, David Rientjes wrote:
>
> On Tue, 29 Sep 2015, Oleg Nesterov wrote:
>
> > The fatal_signal_pending() was added to suppress unnecessary "sharing
> > same memory" message, but it can't 100% help anyway because it can be
> > false-negative; SIGKILL can be already dequeued.
> >
> > And worse, it can be false-positive due to exec or coredump. exec is
> > mostly fine, but coredump is not. 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.
> >
> > We could probably add the additional ->group_exit_task check but this
> > pach just removes fatal_signal_pending(), the extra "Kill process" is
> > unlikely and doesn't really hurt.
> >
> > Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
>
> Acked-by: David Rientjes <rientjes@xxxxxxxxxx>

Thanks!

> In addition, I'm really debating whether we need the "sharing same memory"
> line or not. In the past, it has been helpful because there is no other
> way to determine what the kernel has killed other than to leave an
> artifact behind in the kernel log. I can imagine that this could easily
> spam the kernel log, though, accompanied by oom killer messages that are
> already very verbose. I wouldn't mind if it the printk were removed
> entirely.

Yes, me too... let me reply to Tetsuo's email.

Oleg.

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