linux/arch/ia64/mm
Mike Kravetz 57a196a584 hugetlb: simplify hugetlb handling in follow_page_mask
During discussions of this series [1], it was suggested that hugetlb
handling code in follow_page_mask could be simplified.  At the beginning
of follow_page_mask, there currently is a call to follow_huge_addr which
'may' handle hugetlb pages.  ia64 is the only architecture which provides
a follow_huge_addr routine that does not return error.  Instead, at each
level of the page table a check is made for a hugetlb entry.  If a hugetlb
entry is found, a call to a routine associated with that entry is made.

Currently, there are two checks for hugetlb entries at each page table
level.  The first check is of the form:

        if (p?d_huge())
                page = follow_huge_p?d();

the second check is of the form:

        if (is_hugepd())
                page = follow_huge_pd().

We can replace these checks, as well as the special handling routines such
as follow_huge_p?d() and follow_huge_pd() with a single routine to handle
hugetlb vmas.

A new routine hugetlb_follow_page_mask is called for hugetlb vmas at the
beginning of follow_page_mask.  hugetlb_follow_page_mask will use the
existing routine huge_pte_offset to walk page tables looking for hugetlb
entries.  huge_pte_offset can be overwritten by architectures, and already
handles special cases such as hugepd entries.

[1] https://lore.kernel.org/linux-mm/cover.1661240170.git.baolin.wang@linux.alibaba.com/

[mike.kravetz@oracle.com: remove vma (pmd sharing) per Peter]
  Link: https://lkml.kernel.org/r/20221028181108.119432-1-mike.kravetz@oracle.com
[mike.kravetz@oracle.com: remove left over hugetlb_vma_unlock_read()]
  Link: https://lkml.kernel.org/r/20221030225825.40872-1-mike.kravetz@oracle.com
Link: https://lkml.kernel.org/r/20220919021348.22151-1-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-08 17:37:10 -08:00
..
contig.c memblock: allow to specify flags with memblock_add_node() 2021-11-06 13:30:42 -07:00
discontig.c mm, memory_hotplug: drop arch_free_nodedata 2022-03-22 15:57:10 -07:00
extable.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fault.c mm: avoid unnecessary page fault retires on shared memory types 2022-06-16 19:48:27 -07:00
hugetlbpage.c hugetlb: simplify hugetlb handling in follow_page_mask 2022-11-08 17:37:10 -08:00
init.c ia64/mm: enable ARCH_HAS_VM_GET_PAGE_PROT 2022-07-17 17:14:40 -07:00
ioremap.c ia64: Remove mm.h from asm/uaccess.h 2020-03-21 16:00:22 +01:00
Makefile ia64: drop marked broken DISCONTIGMEM and VIRTUAL_MEM_MAP 2021-04-30 11:20:35 -07:00
numa.c ia64: export memory_add_physaddr_to_nid to fix cxl build error 2022-09-12 15:36:09 +02:00
tlb.c ia64: fix typos in comments 2022-04-28 23:17:25 -07:00