Re: [RFC PATCH 4/4] hugetlb: add support for preferred node to alloc_huge_page_nodemask

[Michal Hocko]

On Thu 08-06-17 10:38:06, Vlastimil Babka wrote:
> On 06/08/2017 09:45 AM, Michal Hocko wrote:
> > From: Michal Hocko <mhocko@xxxxxxxx>
> > 
> > alloc_huge_page_nodemask tries to allocate from any numa node in the
> > allowed node mask. This might lead to filling up low NUMA nodes while
> > others are not used. We can reduce this risk by introducing a concept
> > of the preferred node similar to what we have in the regular page
> > allocator. We will start allocating from the preferred nid and then
> > iterate over all allowed nodes until we try them all. Introduce
> > for_each_node_mask_preferred helper which does the iteration and reuse
> > the available preferred node in new_page_nodemask which is currently
> > the only caller of alloc_huge_page_nodemask.
> > 
> > Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
> 
> That's better, yeah. I don't think it would be too hard to use a
> zonelist though. What do others think?

OK, so I've given it a try. This is untested yet but it doesn't look all
that bad. dequeue_huge_page_node will most proably see some clean up on
top but I've kept it for simplicity for now.
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