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Commit 826fad1b authored by David Rientjes's avatar David Rientjes Committed by Linus Torvalds
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smaps: extract pmd walker from smaps code 



Extracts the pmd walker from smaps-specific code in fs/proc/task_mmu.c.

The new struct pmd_walker includes the struct vm_area_struct of the memory to
walk over.  Iteration begins at the vma->vm_start and completes at
vma->vm_end.  A pointer to another data structure may be stored in the private
field such as struct mem_size_stats, which acts as the smaps accumulator.  For
each pmd in the VMA, the action function is called with a pointer to its
struct vm_area_struct, a pointer to the pmd_t, its start and end addresses,
and the private field.

The interface for walking pmd's in a VMA for fs/proc/task_mmu.c is now:

	void for_each_pmd(struct vm_area_struct *vma,
			  void (*action)(struct vm_area_struct *vma,
					 pmd_t *pmd, unsigned long addr,
					 unsigned long end,
					 void *private),
			  void *private);

Since the pmd walker is now extracted from the smaps code, smaps_one_pmd() is
invoked for each pmd in the VMA.  Its behavior and efficiency is identical to
the existing implementation.

Cc: Hugh Dickins <hugh@veritas.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0013572b

fs/proc/task_mmu.c

+42 −27
Original line number Diff line number Diff line
@@ -122,6 +122,13 @@ struct mem_size_stats 
	unsigned long private_dirty;

};



struct pmd_walker {

	struct vm_area_struct *vma;

	void *private;

	void (*action)(struct vm_area_struct *, pmd_t *, unsigned long,

		       unsigned long, void *);

};



static int show_map_internal(struct seq_file *m, void *v, struct mem_size_stats *mss)

{

	struct proc_maps_private *priv = m->private;
@@ -204,16 +211,17 @@ static int show_map(struct seq_file *m, void *v) 
	return show_map_internal(m, v, NULL);

}



static void smaps_pte_range(struct vm_area_struct *vma, pmd_t *pmd,

static void smaps_one_pmd(struct vm_area_struct *vma, pmd_t *pmd,

			  unsigned long addr, unsigned long end,

				struct mem_size_stats *mss)

			  void *private)

{

	struct mem_size_stats *mss = private;

	pte_t *pte, ptent;

	spinlock_t *ptl;

	struct page *page;



	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);

	do {

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

		ptent = *pte;

		if (!pte_present(ptent))

			continue;
@@ -235,57 +243,64 @@ static void smaps_pte_range(struct vm_area_struct *vma, pmd_t *pmd, 
			else

				mss->private_clean += PAGE_SIZE;

		}

	} while (pte++, addr += PAGE_SIZE, addr != end);

	}

	pte_unmap_unlock(pte - 1, ptl);

	cond_resched();

}



static inline void smaps_pmd_range(struct vm_area_struct *vma, pud_t *pud,

				unsigned long addr, unsigned long end,

				struct mem_size_stats *mss)

static inline void for_each_pmd_in_pud(struct pmd_walker *walker, pud_t *pud,

				       unsigned long addr, unsigned long end)

{

	pmd_t *pmd;

	unsigned long next;



	pmd = pmd_offset(pud, addr);

	do {

	for (pmd = pmd_offset(pud, addr); addr != end;

	     pmd++, addr = next) {

		next = pmd_addr_end(addr, end);

		if (pmd_none_or_clear_bad(pmd))

			continue;

		smaps_pte_range(vma, pmd, addr, next, mss);

	} while (pmd++, addr = next, addr != end);

		walker->action(walker->vma, pmd, addr, next, walker->private);

	}

}



static inline void smaps_pud_range(struct vm_area_struct *vma, pgd_t *pgd,

				unsigned long addr, unsigned long end,

				struct mem_size_stats *mss)

static inline void for_each_pud_in_pgd(struct pmd_walker *walker, pgd_t *pgd,

				       unsigned long addr, unsigned long end)

{

	pud_t *pud;

	unsigned long next;



	pud = pud_offset(pgd, addr);

	do {

	for (pud = pud_offset(pgd, addr); addr != end;

	     pud++, addr = next) {

		next = pud_addr_end(addr, end);

		if (pud_none_or_clear_bad(pud))

			continue;

		smaps_pmd_range(vma, pud, addr, next, mss);

	} while (pud++, addr = next, addr != end);

		for_each_pmd_in_pud(walker, pud, addr, next);

	}

}



static inline void smaps_pgd_range(struct vm_area_struct *vma,

				unsigned long addr, unsigned long end,

				struct mem_size_stats *mss)

static inline void for_each_pmd(struct vm_area_struct *vma,

				void (*action)(struct vm_area_struct *, pmd_t *,

					       unsigned long, unsigned long,

					       void *),

				void *private)

{

	unsigned long addr = vma->vm_start;

	unsigned long end = vma->vm_end;

	struct pmd_walker walker = {

		.vma		= vma,

		.private	= private,

		.action		= action,

	};

	pgd_t *pgd;

	unsigned long next;



	pgd = pgd_offset(vma->vm_mm, addr);

	do {

	for (pgd = pgd_offset(vma->vm_mm, addr); addr != end;

	     pgd++, addr = next) {

		next = pgd_addr_end(addr, end);

		if (pgd_none_or_clear_bad(pgd))

			continue;

		smaps_pud_range(vma, pgd, addr, next, mss);

	} while (pgd++, addr = next, addr != end);

		for_each_pud_in_pgd(&walker, pgd, addr, next);

	}

}



static int show_smap(struct seq_file *m, void *v)
@@ -295,7 +310,7 @@ static int show_smap(struct seq_file *m, void *v) 


	memset(&mss, 0, sizeof mss);

	if (vma->vm_mm && !is_vm_hugetlb_page(vma))

		smaps_pgd_range(vma, vma->vm_start, vma->vm_end, &mss);

		for_each_pmd(vma, smaps_one_pmd, &mss);

	return show_map_internal(m, v, &mss);

}