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 <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>
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 91b46f9..9af86f3 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);
}