4.12-rc ppc64 4k-page needs costly allocations

[Christoph Lameter]

> > I am curious as to what is going on there. Do you have the output from
> > these failed allocations?
>
> I thought the relevant output was in my mail.  I did skip the Mem-Info
> dump, since that just seemed noise in this case: we know memory can get
> fragmented.  What more output are you looking for?

The output for the failing allocations when you disabling debugging. For
that I would think that you need remove(!) the slub_debug statement on the kernel
command line. You can verify that debug is off by inspecting the values in
/sys/kernel/slab/<yourcache>/<debug option>

> But it was still order 4 when booted with slub_debug=O, which surprised me.
> And that surprises you too?  If so, then we ought to dig into it further.

No it does no longer. I dont think slub_debug=O does disable debugging
(frankly I am not sure what it does). Please do not specify any debug options.