Re: [patch 2/3] Fix GFP_THISNODE behavior for memoryless nodes

Christoph Lameter
2007-06-14T15:51:13Z

On Thu, 14 Jun 2007, Lee Schermerhorn wrote:

> > It is able to handle NULLs during usual operations but not during bootstrap.
>
> ??? it has to handle memoryless nodes, right? if so, why can't it
> handle alloc_pages_node('THISNODE,...) returning NULL? Too late in the
> process?

It should not call alloc_pages_node for a node that has no memory during
bootstrap.

> Or do you mean that GPF_THISNODE should return memory from the lower
> zones, if it satisfies the order requirement? Your custom 'thisnode'
> zonelist will enable this, right? That would work for my particular
> config of my platform, but on a larger platform, I'd have a larger DMA
> zone and wouldn't want hugetlb pages coming from there.

Right. The fixes here are for the general vm and not for hugetlb. They are
definitely not HP platform specific.

> I guess that in the long run, I need to hope that Nish's per node huge
> page attribute goes in. Then, we can provide a fancy script to configure
> huge pages on a specific set of nodes, rather than relying on the kernel
> to distribute them evenly across the set of nodes that "make sense" for
> the given platform.

Right.