[PATCH 0/6] hugetlbfs: support free page reporting

[Liang Li]

A typical usage of hugetlbfs it's to reserve amount of memory
during the kernel booting stage, and the reserved pages are
unlikely to return to the buddy system. When application need
hugepages, kernel will allocate them from the reserved pool.
when application terminates, huge pages will return to the
reserved pool and are kept in the free list for hugetlbfs,
these free pages will not return to buddy freelist unless the
size of reserved pool is changed. 
Free page reporting only supports buddy pages, it can't report
the free pages reserved for hugetlbfs. On the other hand,
hugetlbfs is a good choice for system with a huge amount of RAM,
because it can help to reduce the memory management overhead and
improve system performance.
This patch add the support for reporting hugepages in the free
list of hugetlbfs, it can be used by virtio_balloon driver for
memory overcommit and pre zero out free pages for speeding up
memory population and page fault handling.

Most of the code are 'copied' from free page reporting because
they are working in the same way. So the code can be refined to
remove duplication. It can be done later.

Since some guys have some concern about side effect of the 'buddy
free page pre zero out' feature brings, I remove it from this
serier.

Liang Li (6):
  mm: Add batch size for free page reporting
  mm: let user decide page reporting option
  hugetlb: add free page reporting support
  hugetlb: avoid allocation failed when page reporting is on going
  virtio-balloon: reporting hugetlb free page to host
  hugetlb: support free hugepage pre zero out

 drivers/virtio/virtio_balloon.c |  58 +++++-
 include/linux/hugetlb.h         |   5 +
 include/linux/page-flags.h      |  12 ++
 include/linux/page_reporting.h  |   7 +
 mm/Kconfig                      |  11 ++
 mm/huge_memory.c                |   3 +-
 mm/hugetlb.c                    | 271 +++++++++++++++++++++++++++
 mm/memory.c                     |   4 +
 mm/page_reporting.c             | 315 +++++++++++++++++++++++++++++++-
 mm/page_reporting.h             |  50 ++++-
 10 files changed, 725 insertions(+), 11 deletions(-)

-- 
2.18.2