Commit 25ee01a2 authored by Naoya Horiguchi's avatar Naoya Horiguchi Committed by Linus Torvalds
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mm: hugetlb: proc: add hugetlb-related fields to /proc/PID/smaps 



Currently /proc/PID/smaps provides no usage info for vma(VM_HUGETLB),
which is inconvenient when we want to know per-task or per-vma base
hugetlb usage.  To solve this, this patch adds new fields for hugetlb
usage like below:

  Size:              20480 kB
  Rss:                   0 kB
  Pss:                   0 kB
  Shared_Clean:          0 kB
  Shared_Dirty:          0 kB
  Private_Clean:         0 kB
  Private_Dirty:         0 kB
  Referenced:            0 kB
  Anonymous:             0 kB
  AnonHugePages:         0 kB
  Shared_Hugetlb:    18432 kB
  Private_Hugetlb:    2048 kB
  Swap:                  0 kB
  KernelPageSize:     2048 kB
  MMUPageSize:        2048 kB
  Locked:                0 kB
  VmFlags: rd wr mr mw me de ht

[hughd@google.com: fix Private_Hugetlb alignment ]
Signed-off-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: default avatarJoern Engel <joern@logfs.org>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.cz>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: default avatarHugh Dickins <hughd@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 600e19af

Documentation/filesystems/proc.txt

+8 −0
Original line number Diff line number Diff line
@@ -424,6 +424,9 @@ Private_Clean: 0 kB 
Private_Dirty:         0 kB

Referenced:          892 kB

Anonymous:             0 kB

AnonHugePages:         0 kB

Shared_Hugetlb:        0 kB

Private_Hugetlb:       0 kB

Swap:                  0 kB

SwapPss:               0 kB

KernelPageSize:        4 kB
@@ -452,6 +455,11 @@ and a page is modified, the file page is replaced by a private anonymous copy. 
"Swap" shows how much would-be-anonymous memory is also used, but out on

swap.

"SwapPss" shows proportional swap share of this mapping.

"AnonHugePages" shows the ammount of memory backed by transparent hugepage.

"Shared_Hugetlb" and "Private_Hugetlb" show the ammounts of memory backed by

hugetlbfs page which is *not* counted in "RSS" or "PSS" field for historical

reasons. And these are not included in {Shared,Private}_{Clean,Dirty} field.



"VmFlags" field deserves a separate description. This member represents the kernel

flags associated with the particular virtual memory area in two letter encoded

manner. The codes are the following:

fs/proc/task_mmu.c

+38 −0
Original line number Diff line number Diff line
@@ -446,6 +446,8 @@ struct mem_size_stats { 
	unsigned long anonymous;

	unsigned long anonymous_thp;

	unsigned long swap;

	unsigned long shared_hugetlb;

	unsigned long private_hugetlb;

	u64 pss;

	u64 swap_pss;

};
@@ -625,12 +627,44 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) 
	seq_putc(m, '\n');

}



#ifdef CONFIG_HUGETLB_PAGE

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

				 unsigned long addr, unsigned long end,

				 struct mm_walk *walk)

{

	struct mem_size_stats *mss = walk->private;

	struct vm_area_struct *vma = walk->vma;

	struct page *page = NULL;



	if (pte_present(*pte)) {

		page = vm_normal_page(vma, addr, *pte);

	} else if (is_swap_pte(*pte)) {

		swp_entry_t swpent = pte_to_swp_entry(*pte);



		if (is_migration_entry(swpent))

			page = migration_entry_to_page(swpent);

	}

	if (page) {

		int mapcount = page_mapcount(page);



		if (mapcount >= 2)

			mss->shared_hugetlb += huge_page_size(hstate_vma(vma));

		else

			mss->private_hugetlb += huge_page_size(hstate_vma(vma));

	}

	return 0;

}

#endif /* HUGETLB_PAGE */



static int show_smap(struct seq_file *m, void *v, int is_pid)

{

	struct vm_area_struct *vma = v;

	struct mem_size_stats mss;

	struct mm_walk smaps_walk = {

		.pmd_entry = smaps_pte_range,

#ifdef CONFIG_HUGETLB_PAGE

		.hugetlb_entry = smaps_hugetlb_range,

#endif

		.mm = vma->vm_mm,

		.private = &mss,

	};
@@ -652,6 +686,8 @@ static int show_smap(struct seq_file *m, void *v, int is_pid) 
		   "Referenced:     %8lu kB\n"

		   "Anonymous:      %8lu kB\n"

		   "AnonHugePages:  %8lu kB\n"

		   "Shared_Hugetlb: %8lu kB\n"

		   "Private_Hugetlb: %7lu kB\n"

		   "Swap:           %8lu kB\n"

		   "SwapPss:        %8lu kB\n"

		   "KernelPageSize: %8lu kB\n"
@@ -667,6 +703,8 @@ static int show_smap(struct seq_file *m, void *v, int is_pid) 
		   mss.referenced >> 10,

		   mss.anonymous >> 10,

		   mss.anonymous_thp >> 10,

		   mss.shared_hugetlb >> 10,

		   mss.private_hugetlb >> 10,

		   mss.swap >> 10,

		   (unsigned long)(mss.swap_pss >> (10 + PSS_SHIFT)),

		   vma_kernel_pagesize(vma) >> 10,

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