4.12-rc ppc64 4k-page needs costly allocations

[Christoph Lameter]

On Wed, 31 May 2017, Michael Ellerman wrote:

> > SLUB: Unable to allocate memory on node -1, gfp=0x14000c0(GFP_KERNEL)
> >   cache: pgtable-2^12, object size: 32768, buffer size: 65536, default order: 4, min order: 4
> >   pgtable-2^12 debugging increased min order, use slub_debug=O to disable.

Ahh. Ok debugging increased the object size to an order 4. This should be
order 3 without debugging.

> > I did try booting with slub_debug=O as the message suggested, but that
> > made no difference: it still hoped for but failed on order:4 allocations.

I am curious as to what is going on there. Do you have the output from
these failed allocations?