Re: [PATCH 1/5] mm: Add __GFP_NO_OOM_KILL flag

Rafael J. Wysocki
2009-05-07T23:24:18Z

On Friday 08 May 2009, Andrew Morton wrote:
> On Fri, 8 May 2009 00:50:41 +0200
> "Rafael J. Wysocki" <rjw-KKrjLPT3xs0@public.gmane.org> wrote:
>
> > On Friday 08 May 2009, Andrew Morton wrote:
> > > On Fri, 8 May 2009 00:14:48 +0200
> > > "Rafael J. Wysocki" <rjw-KKrjLPT3xs0@public.gmane.org> wrote:
> > >
> > > > IOW, you need to freeze the user space totally before trying to disable the
> > > > OOM killer.
> > >
> > > Not necessarily. We only need to take action if a task is about to
> > > start oom-killing - presumably by taking a nap.
> > >
> > > If a process is sitting there happily computing pi then we can leave it
> > > running.
> >
> > Well, the point is we don't really know what the task is going to do next.
> > Is it going to continue computing pi, or is it going to execl(huge_binary), for
> > example?
> >
> > If we knew what tasks were going to do in advance, the whole freezing wouldn't
> > really be necessary. :-)
>
> argh. Third time:
>
> - if the task is computing pi, let it do so.
>
> - if the task tries to allocate memory and succeeds, let it proceed.
>
> - if the task tries to allocate memory and fails and then tries to invoke
> the oom-killer, stop the task.

Understood.