From b4e98d9ac775907cc53fb08fcb6776deb7694e30 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Wed, 15 Nov 2017 17:35:33 -0800 Subject: mm: account pud page tables 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 dc6c9a35b66b ("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 Signed-off-by: Heiko Carstens Acked-by: Rik van Riel Acked-by: Michal Hocko Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mm.h | 36 +++++++++++++++++++++++++++++++++--- 1 file changed, 33 insertions(+), 3 deletions(-) (limited to 'include/linux/mm.h') diff --git a/include/linux/mm.h b/include/linux/mm.h index 91b46f99b4d2..9af86f39d928 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -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); } -- cgit