On 9/19/2022 10:13 AM, Mike Kravetz wrote:
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@xxxxxxxxxxxxxxxxx/
Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
LGTM, and works well on my machine. So feel free to add: Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> Tested-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
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