diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2017-11-16 02:35:33 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-16 03:21:04 +0100 |
| commit | b4e98d9ac775907cc53fb08fcb6776deb7694e30 (patch) | |
| tree | 4a82caff5eab86a66f078622acfd68df5ac92235 /mm/memory.c | |
| parent | kmemleak: change /sys/kernel/debug/kmemleak permissions from 0444 to 0644 (diff) | |
| download | linux-b4e98d9ac775907cc53fb08fcb6776deb7694e30.tar.xz linux-b4e98d9ac775907cc53fb08fcb6776deb7694e30.zip | |
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>
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/mm/memory.c b/mm/memory.c index 42fb30300bb5..6bbd4078ec98 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -506,6 +506,7 @@ static inline void free_pud_range(struct mmu_gather *tlb, p4d_t *p4d, pud = pud_offset(p4d, start); p4d_clear(p4d); pud_free_tlb(tlb, pud, start); + mm_dec_nr_puds(tlb->mm); } static inline void free_p4d_range(struct mmu_gather *tlb, pgd_t *pgd, @@ -4149,15 +4150,17 @@ int __pud_alloc(struct mm_struct *mm, p4d_t *p4d, unsigned long address) spin_lock(&mm->page_table_lock); #ifndef __ARCH_HAS_5LEVEL_HACK - if (p4d_present(*p4d)) /* Another has populated it */ - pud_free(mm, new); - else + if (!p4d_present(*p4d)) { + mm_inc_nr_puds(mm); p4d_populate(mm, p4d, new); -#else - if (pgd_present(*p4d)) /* Another has populated it */ + } else /* Another has populated it */ pud_free(mm, new); - else +#else + if (!pgd_present(*p4d)) { + mm_inc_nr_puds(mm); pgd_populate(mm, p4d, new); + } else /* Another has populated it */ + pud_free(mm, new); #endif /* __ARCH_HAS_5LEVEL_HACK */ spin_unlock(&mm->page_table_lock); return 0; |