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Commit 356515e7 authored by Konstantin Khlebnikov's avatar Konstantin Khlebnikov Committed by Linus Torvalds
Browse files

pagemap: rework hugetlb and thp report 



This patch moves pmd dissection out of reporting loop: huge pages are
reported as bunch of normal pages with contiguous PFNs.

Add missing "FILE" bit in hugetlb vmas.

Signed-off-by: default avatarKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: default avatarMark Williamson <mwilliamson@undo-software.com>
Tested-by: default avatarMark Williamson <mwilliamson@undo-software.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent deb94544

fs/proc/task_mmu.c

+44 −56
Original line number Diff line number Diff line
@@ -1040,33 +1040,7 @@ static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm, 
	return make_pme(frame, flags);

}



#ifdef CONFIG_TRANSPARENT_HUGEPAGE

static pagemap_entry_t thp_pmd_to_pagemap_entry(struct pagemapread *pm,

		pmd_t pmd, int offset, u64 flags)

{

	u64 frame = 0;



	/*

	 * Currently pmd for thp is always present because thp can not be

	 * swapped-out, migrated, or HWPOISONed (split in such cases instead.)

	 * This if-check is just to prepare for future implementation.

	 */

	if (pmd_present(pmd)) {

		frame = pmd_pfn(pmd) + offset;

		flags |= PM_PRESENT;

	}



	return make_pme(frame, flags);

}

#else

static pagemap_entry_t thp_pmd_to_pagemap_entry(struct pagemapread *pm,

		pmd_t pmd, int offset, u64 flags)

{

	return make_pme(0, 0);

}

#endif



static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,

static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,

			     struct mm_walk *walk)

{

	struct vm_area_struct *vma = walk->vma;
@@ -1075,35 +1049,48 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, 
	pte_t *pte, *orig_pte;

	int err = 0;



	if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {

		u64 flags = 0;

#ifdef CONFIG_TRANSPARENT_HUGEPAGE

	if (pmd_trans_huge_lock(pmdp, vma, &ptl) == 1) {

		u64 flags = 0, frame = 0;

		pmd_t pmd = *pmdp;



		if ((vma->vm_flags & VM_SOFTDIRTY) || pmd_soft_dirty(*pmd))

		if ((vma->vm_flags & VM_SOFTDIRTY) || pmd_soft_dirty(pmd))

			flags |= PM_SOFT_DIRTY;



		/*

		 * Currently pmd for thp is always present because thp

		 * can not be swapped-out, migrated, or HWPOISONed

		 * (split in such cases instead.)

		 * This if-check is just to prepare for future implementation.

		 */

		if (pmd_present(pmd)) {

			flags |= PM_PRESENT;

			frame = pmd_pfn(pmd) +

				((addr & ~PMD_MASK) >> PAGE_SHIFT);

		}



		for (; addr != end; addr += PAGE_SIZE) {

			unsigned long offset;

			pagemap_entry_t pme;

			pagemap_entry_t pme = make_pme(frame, flags);



			offset = (addr & ~PAGEMAP_WALK_MASK) >>

					PAGE_SHIFT;

			pme = thp_pmd_to_pagemap_entry(pm, *pmd, offset, flags);

			err = add_to_pagemap(addr, &pme, pm);

			if (err)

				break;

			if (flags & PM_PRESENT)

				frame++;

		}

		spin_unlock(ptl);

		return err;

	}



	if (pmd_trans_unstable(pmd))

	if (pmd_trans_unstable(pmdp))

		return 0;

#endif /* CONFIG_TRANSPARENT_HUGEPAGE */



	/*

	 * We can assume that @vma always points to a valid one and @end never

	 * goes beyond vma->vm_end.

	 */

	orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);

	orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl);

	for (; addr < end; pte++, addr += PAGE_SIZE) {

		pagemap_entry_t pme;
@@ -1120,39 +1107,40 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, 
}



#ifdef CONFIG_HUGETLB_PAGE

static pagemap_entry_t huge_pte_to_pagemap_entry(struct pagemapread *pm,

					pte_t pte, int offset, u64 flags)

{

	u64 frame = 0;



	if (pte_present(pte)) {

		frame = pte_pfn(pte) + offset;

		flags |= PM_PRESENT;

	}



	return make_pme(frame, flags);

}



/* This function walks within one hugetlb entry in the single call */

static int pagemap_hugetlb_range(pte_t *pte, unsigned long hmask,

static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,

				 unsigned long addr, unsigned long end,

				 struct mm_walk *walk)

{

	struct pagemapread *pm = walk->private;

	struct vm_area_struct *vma = walk->vma;

	u64 flags = 0, frame = 0;

	int err = 0;

	u64 flags = 0;

	pagemap_entry_t pme;

	pte_t pte;



	if (vma->vm_flags & VM_SOFTDIRTY)

		flags |= PM_SOFT_DIRTY;



	pte = huge_ptep_get(ptep);

	if (pte_present(pte)) {

		struct page *page = pte_page(pte);



		if (!PageAnon(page))

			flags |= PM_FILE;



		flags |= PM_PRESENT;

		frame = pte_pfn(pte) +

			((addr & ~hmask) >> PAGE_SHIFT);

	}



	for (; addr != end; addr += PAGE_SIZE) {

		int offset = (addr & ~hmask) >> PAGE_SHIFT;

		pme = huge_pte_to_pagemap_entry(pm, *pte, offset, flags);

		pagemap_entry_t pme = make_pme(frame, flags);



		err = add_to_pagemap(addr, &pme, pm);

		if (err)

			return err;

		if (flags & PM_PRESENT)

			frame++;

	}



	cond_resched();
@@ -1216,7 +1204,7 @@ static ssize_t pagemap_read(struct file *file, char __user *buf, 
	if (!pm.buffer)

		goto out_mm;



	pagemap_walk.pmd_entry = pagemap_pte_range;

	pagemap_walk.pmd_entry = pagemap_pmd_range;

	pagemap_walk.pte_hole = pagemap_pte_hole;

#ifdef CONFIG_HUGETLB_PAGE

	pagemap_walk.hugetlb_entry = pagemap_hugetlb_range;