[PATCH mm-unstable v1 0/3] mm/hugetlb: alloc/free gigantic folios

[Yu Zhao]

Use __GFP_COMP for gigantic folios can greatly reduce not only the
complexity in the code but also the allocation and free time.

Approximate LOC to mm/hugetlb.c: -200, +50

Allocate and free 500 1GB hugeTLB memory without HVO by:
  time echo 500 >/sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages
  time echo 0 >/sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages

       Before  After
Alloc  ~13s    ~10s
Free   ~15s    <1s

The above magnitude generally holds for multiple x86 and arm64 CPU
models.

Yu Zhao (3):
  mm/contig_alloc: support __GFP_COMP
  mm/cma: add cma_alloc_folio()
  mm/hugetlb: use __GFP_COMP for gigantic folios

 include/linux/cma.h     |   1 +
 include/linux/hugetlb.h |   9 +-
 mm/cma.c                |  47 +++++---
 mm/compaction.c         |  48 +-------
 mm/hugetlb.c            | 244 ++++++++--------------------------------
 mm/internal.h           |   9 ++
 mm/page_alloc.c         | 111 +++++++++++++-----
 7 files changed, 177 insertions(+), 292 deletions(-)


base-commit: b447504e1fed49fabbc03d6c2530126824f87c92
prerequisite-patch-id: 9fe502f7c87a9f951d0aee61f426bd85bc43ef74
-- 
2.46.0.76.ge559c4bf1a-goog