Re: [resend][PATCH 2/4] Revert "oom: deprecate oom_adj tunable"

From: KOSAKI Motohiro
Date: Tue Nov 30 2010 - 08:03:50 EST


> On Tue, 23 Nov 2010, KOSAKI Motohiro wrote:
>
> > > > No irrelevant. Your patch break their environment even though
> > > > they don't use oom_adj explicitly. because their application are using it.
> > > >
> > >
> > > The _only_ difference too oom_adj since the rewrite is that it is now
> > > mapped on a linear scale rather than an exponential scale.
> >
> > _only_ mean don't ZERO different. Why do userland application need to rewrite?
> >
>
> Because NOTHING breaks with the new mapping. Eight months later since
> this was initially proposed on linux-mm, you still cannot show a single
> example that depended on the exponential mapping of oom_adj. I'm not
> going to continue responding to your criticism about this point since your
> argument is completely and utterly baseless.

No regression mean no break. Not single nor multiple. see?


>
> > Again, IF you need to [0 .. 1000] range, you can calculate it by your
> > application. current oom score can be get from /proc/pid/oom_score and
> > total memory can be get from /proc/meminfo. You shouldn't have break
> > anything.
> >
>
> That would require the userspace tunable to be adjusted anytime a task's
> mempolicy changes, its nodemask changes, it's cpuset attachment changes,

All situation can be calculated on userland. User process can be know
their bindings.



> its mems change, a memcg limit changes, etc. The only constant is the
> task's priority, and the current oom_score_adj implementation preserves
> that unless explicitly changed later by the user. I completely understand
> that you may not have a use for this.



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/