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Commit bca15543 authored by Konstantin Khlebnikov's avatar Konstantin Khlebnikov Committed by Linus Torvalds
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proc/smaps: show amount of nonlinear ptes in vma 



Currently, nonlinear mappings can not be distinguished from ordinary
mappings.  This patch adds into /proc/pid/smaps line "Nonlinear: <size>
kB", where size is amount of nonlinear ptes in vma, this line appears only
if VM_NONLINEAR is set.  This information may be useful not only for
checkpoint/restore project.

Requested by Pavel Emelyanov.

Signed-off-by: default avatarKonstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b1d4d9e0

fs/proc/task_mmu.c

+12 −0
Original line number Diff line number Diff line
@@ -393,6 +393,7 @@ struct mem_size_stats { 
	unsigned long anonymous;

	unsigned long anonymous_thp;

	unsigned long swap;

	unsigned long nonlinear;

	u64 pss;

};
@@ -402,6 +403,7 @@ static void smaps_pte_entry(pte_t ptent, unsigned long addr, 
{

	struct mem_size_stats *mss = walk->private;

	struct vm_area_struct *vma = mss->vma;

	pgoff_t pgoff = linear_page_index(vma, addr);

	struct page *page = NULL;

	int mapcount;
@@ -414,6 +416,9 @@ static void smaps_pte_entry(pte_t ptent, unsigned long addr, 
			mss->swap += ptent_size;

		else if (is_migration_entry(swpent))

			page = migration_entry_to_page(swpent);

	} else if (pte_file(ptent)) {

		if (pte_to_pgoff(ptent) != pgoff)

			mss->nonlinear += ptent_size;

	}



	if (!page)
@@ -422,6 +427,9 @@ static void smaps_pte_entry(pte_t ptent, unsigned long addr, 
	if (PageAnon(page))

		mss->anonymous += ptent_size;



	if (page->index != pgoff)

		mss->nonlinear += ptent_size;



	mss->resident += ptent_size;

	/* Accumulate the size in pages that have been accessed. */

	if (pte_young(ptent) || PageReferenced(page))
@@ -523,6 +531,10 @@ static int show_smap(struct seq_file *m, void *v, int is_pid) 
		   (vma->vm_flags & VM_LOCKED) ?

			(unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0);



	if (vma->vm_flags & VM_NONLINEAR)

		seq_printf(m, "Nonlinear:      %8lu kB\n",

				mss.nonlinear >> 10);



	if (m->count < m->size)  /* vma is copied successfully */

		m->version = (vma != get_gate_vma(task->mm))

			? vma->vm_start : 0;