[PATCH mm-unstable v5 00/10] convert core hugetlb functions to folios

Sidhartha Kumar
2022-11-29T22:51:24Z

============== OVERVIEW ===========================
Now that many hugetlb helper functions that deal with hugetlb specific
flags[1] and hugetlb cgroups[2] are converted to folios, higher level
allocation, prep, and freeing functions within hugetlb can also be
converted to operate in folios.

Patch 1 of this series implements the wrapper functions around setting
the compound destructor and compound order for a folio. Besides the user
added in patch 1, patch 2 and patch 9 also use these helper functions.

Patches 2-10 convert the higher level hugetlb functions to folios.

============== TESTING ===========================
LTP:
Ran 10 back to back rounds of the LTP hugetlb test suite.

Gigantic Huge Pages:
Test allocation and freeing via hugeadm commands:
hugeadm --pool-pages-min 1GB:10
hugeadm --pool-pages-min 1GB:0

Demote:
Demote 1 1GB hugepages to 512 2MB hugepages
echo 1 > /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages
echo 1 > /sys/kernel/mm/hugepages/hugepages-1048576kB/demote
cat /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
# 512
cat /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages
# 0

Rebased on 10/29/2022 mm-unstable

[1] https://lore.kernel.org/lkml/20220922154207.1575343-1-sidhartha.kumar@oracle.com/
[2] https://lore.kernel.org/linux-mm/20221101223059.460937-1-sidhartha.kumar@oracle.com/

v1 -> v2:
- fix conflict with "mm,thp,rmap: simplify compound page mapcount handling"
v2 -> v3:
- v2 contained wrong version of patch 1
v3 -> v4:
- change instances of folio_{clear, set}_head() to __folio_{clear, set}_head()
- rebase on top of hugetlb: Fix __prep_compound_gigantic_page page flag setting
v4 -> v5:
- change comment with HPageVmemmapOptimized to hugetlb_vmemmap_optimized
per Tarun Sahu
- fix Smatch warning in patch 10 by reorganizing alloc_pool_huge_page
- fix NULL pointer dereference issue in patch 10 per John Hubbard
- use NULL rather than 0 in patch 6 per David Hildenbrand

Sidhartha Kumar (10):
mm: add folio dtor and order setter functions
mm/hugetlb: convert destroy_compound_gigantic_page() to folios
mm/hugetlb: convert dissolve_free_huge_page() to folios
mm/hugetlb: convert remove_hugetlb_page() to folios
mm/hugetlb: convert update_and_free_page() to folios
mm/hugetlb: convert add_hugetlb_page() to folios and add
hugetlb_cma_folio()
mm/hugetlb: convert enqueue_huge_page() to folios
mm/hugetlb: convert free_gigantic_page() to folios
mm/hugetlb: convert hugetlb prep functions to folios
mm/hugetlb: change hugetlb allocation functions to return a folio

include/linux/mm.h | 16 ++
mm/hugetlb.c | 409 ++++++++++++++++++++++-----------------------
2 files changed, 219 insertions(+), 206 deletions(-)

--
2.38.1