Re: [PATCH] mm: rename and document alloc_pages_exact_node

Christoph Lameter
2015-07-23T14:11:53Z

On Wed, 22 Jul 2015, David Rientjes wrote:

> Eek, yeah, that does look bad. I'm not even sure the
>
> if (nid < 0)
> nid = numa_node_id();
>
> is correct; I think this should be comparing to NUMA_NO_NODE rather than
> all negative numbers, otherwise we silently ignore overflow and nobody
> ever knows.

Comparing to NUMA_NO_NODE would be better. Also use numa_mem_id() instead
to support memoryless nodes better?

> The only possible downside would be existing users of
> alloc_pages_node() that are calling it with an offline node. Since it's a
> VM_BUG_ON() that would catch that, I think it should be changed to a
> VM_WARN_ON() and eventually fixed up because it's nonsensical.
> VM_BUG_ON() here should be avoided.

The offline node thing could be addresses by using numa_mem_id()?