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mm: account pud page tables

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On a machine with 5-level paging support a process can allocate
significant amount of memory and stay unnoticed by oom-killer and memory
cgroup.  The trick is to allocate a lot of PUD page tables.  We don't
account PUD page tables, only PMD and PTE.

We already addressed the same issue for PMD page tables, see commit
dc6c9a35b6 ("mm: account pmd page tables to the process").
Introduction of 5-level paging brings the same issue for PUD page
tables.

The patch expands accounting to PUD level.

[kirill.shutemov@linux.intel.com: s/pmd_t/pud_t/]
  Link: http://lkml.kernel.org/r/20171004074305.x35eh5u7ybbt5kar@black.fi.intel.com
[heiko.carstens@de.ibm.com: s390/mm: fix pud table accounting]
  Link: http://lkml.kernel.org/r/20171103090551.18231-1-heiko.carstens@de.ibm.com
Link: http://lkml.kernel.org/r/20171002080427.3320-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Kirill A. Shutemov 2017-11-15 17:35:33 -08:00 • committed by Linus Torvalds
parent 7d6c4dfa4d
commit b4e98d9ac7
11 changed files with 71 additions and 20 deletions
Download patch file Download diff file Expand all files Collapse all files

36
include/linux/mm.h
View file

@ -1599,14 +1599,44 @@ static inline int __p4d_alloc(struct mm_struct *mm, pgd_t *pgd,
int __p4d_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
#endif
#ifdef __PAGETABLE_PUD_FOLDED
#if defined(__PAGETABLE_PUD_FOLDED) || !defined(CONFIG_MMU)
static inline int __pud_alloc(struct mm_struct *mm, p4d_t *p4d,
unsigned long address)
{
return 0;
}
static inline unsigned long mm_nr_puds(const struct mm_struct *mm)
{
return 0;
}
static inline void mm_nr_puds_init(struct mm_struct *mm) {}
static inline void mm_inc_nr_puds(struct mm_struct *mm) {}
static inline void mm_dec_nr_puds(struct mm_struct *mm) {}
#else
int __pud_alloc(struct mm_struct *mm, p4d_t *p4d, unsigned long address);
static inline void mm_nr_puds_init(struct mm_struct *mm)
{
atomic_long_set(&mm->nr_puds, 0);
}
static inline unsigned long mm_nr_puds(const struct mm_struct *mm)
{
return atomic_long_read(&mm->nr_puds);
}
static inline void mm_inc_nr_puds(struct mm_struct *mm)
{
atomic_long_inc(&mm->nr_puds);
}
static inline void mm_dec_nr_puds(struct mm_struct *mm)
{
atomic_long_dec(&mm->nr_puds);
}
#endif
#if defined(__PAGETABLE_PMD_FOLDED) || !defined(CONFIG_MMU)
@ -1618,7 +1648,7 @@ static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
static inline void mm_nr_pmds_init(struct mm_struct *mm) {}
static inline unsigned long mm_nr_pmds(struct mm_struct *mm)
static inline unsigned long mm_nr_pmds(const struct mm_struct *mm)
{
return 0;
}
@ -1634,7 +1664,7 @@ static inline void mm_nr_pmds_init(struct mm_struct *mm)
atomic_long_set(&mm->nr_pmds, 0);
}
static inline unsigned long mm_nr_pmds(struct mm_struct *mm)
static inline unsigned long mm_nr_pmds(const struct mm_struct *mm)
{
return atomic_long_read(&mm->nr_pmds);
}

3
include/linux/mm_types.h
View file

@ -404,6 +404,9 @@ struct mm_struct {
atomic_long_t nr_ptes; /* PTE page table pages */
#if CONFIG_PGTABLE_LEVELS > 2
atomic_long_t nr_pmds; /* PMD page table pages */
#endif
#if CONFIG_PGTABLE_LEVELS > 3
atomic_long_t nr_puds; /* PUD page table pages */
#endif
int map_count; /* number of VMAs */