[RFC PATCH 0/4] mm, hugetlb: allow proper node fallback dequeue

[Michal Hocko <mhocko@kernel.org>]

Hi,
while working on a hugetlb migration issue addressed in a separate
patchset [1] I have noticed that the hugetlb allocations from the
preallocated pool are quite subotimal. There is no fallback mechanism
implemented and no notion of preferred node. I have tried to work
around it by [2] but Vlastimil was right to push back for a more robust
solution. It seems that such a solution is to reuse zonelist approach
we use for the page alloctor.

This series has 4 patches. The first one tries to make hugetlb
allocation layers more clear. The second one implements the zonelist
hugetlb pool allocation and introduces a preferred node semantic which
is used by the migration callbacks. The third patch is a pure clean up
as well as the last patch.

Note that this patch depends on [1] (without the last patch which
is replaced by this work). You can find the whole series in
git://git.kernel.org/pub/scm/linux/kernel/git/mhocko/mm.git branch
attempts/hugetlb-zonelists

I am sending this as an RFC because I might be missing some subtle
dependencies which led to the original design.

Shortlog
Michal Hocko (4):
      mm, hugetlb: unclutter hugetlb allocation layers
      hugetlb: add support for preferred node to alloc_huge_page_nodemask
      mm, hugetlb: get rid of dequeue_huge_page_node
      mm, hugetlb, soft_offline: use new_page_nodemask for soft offline migration

And the diffstat looks promissing as well

 include/linux/hugetlb.h |   3 +-
 include/linux/migrate.h |   2 +-
 mm/hugetlb.c            | 233 ++++++++++++++++--------------------------------
 mm/memory-failure.c     |  10 +--
 4 files changed, 82 insertions(+), 166 deletions(-)

[1] http://lkml.kernel.org/r/20170608074553.22152-1-mhocko@kernel.org
[2] http://lkml.kernel.org/r/20170608074553.22152-5-mhocko@kernel.org