Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 0ca1634d authored by Johannes Weiner's avatar Johannes Weiner Committed by Linus Torvalds
Browse files

thp: mincore transparent hugepage support 



Handle transparent huge page pmd entries natively instead of splitting
them into subpages.

Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
Reviewed-by: default avatarRik van Riel <riel@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f2d6bfe9

include/linux/huge_mm.h

+3 −0
Original line number Diff line number Diff line
@@ -19,6 +19,9 @@ extern struct page *follow_trans_huge_pmd(struct mm_struct *mm, 
extern int zap_huge_pmd(struct mmu_gather *tlb,

			struct vm_area_struct *vma,

			pmd_t *pmd);

extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,

			unsigned long addr, unsigned long end,

			unsigned char *vec);



enum transparent_hugepage_flag {

	TRANSPARENT_HUGEPAGE_FLAG,

mm/huge_memory.c

+25 −0
Original line number Diff line number Diff line
@@ -923,6 +923,31 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, 
	return ret;

}



int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,

		unsigned long addr, unsigned long end,

		unsigned char *vec)

{

	int ret = 0;



	spin_lock(&vma->vm_mm->page_table_lock);

	if (likely(pmd_trans_huge(*pmd))) {

		ret = !pmd_trans_splitting(*pmd);

		spin_unlock(&vma->vm_mm->page_table_lock);

		if (unlikely(!ret))

			wait_split_huge_page(vma->anon_vma, pmd);

		else {

			/*

			 * All logical pages in the range are present

			 * if backed by a huge page.

			 */

			memset(vec, 1, (end - addr) >> PAGE_SHIFT);

		}

	} else

		spin_unlock(&vma->vm_mm->page_table_lock);



	return ret;

}



pmd_t *page_check_address_pmd(struct page *page,

			      struct mm_struct *mm,

			      unsigned long address,

mm/mincore.c

+7 −1
Original line number Diff line number Diff line
@@ -154,7 +154,13 @@ static void mincore_pmd_range(struct vm_area_struct *vma, pud_t *pud, 
	pmd = pmd_offset(pud, addr);

	do {

		next = pmd_addr_end(addr, end);

		split_huge_page_pmd(vma->vm_mm, pmd);

		if (pmd_trans_huge(*pmd)) {

			if (mincore_huge_pmd(vma, pmd, addr, next, vec)) {

				vec += (next - addr) >> PAGE_SHIFT;

				continue;

			}

			/* fall through */

		}

		if (pmd_none_or_clear_bad(pmd))

			mincore_unmapped_range(vma, addr, next, vec);

		else