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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2017-11-15 17:35:33 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-11-15 18:21:04 -0800
commitb4e98d9ac775907cc53fb08fcb6776deb7694e30 (patch)
tree4a82caff5eab86a66f078622acfd68df5ac92235 /kernel
parent7d6c4dfa4de96d11b9d6adaf5aa5ca8c54670258 (diff)
downloadlinux-b4e98d9ac775907cc53fb08fcb6776deb7694e30.tar.bz2
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 'kernel')
-rw-r--r--kernel/fork.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index 07cc743698d3..a4eb6f289365 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -819,6 +819,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p,
mm->core_state = NULL;
atomic_long_set(&mm->nr_ptes, 0);
mm_nr_pmds_init(mm);
+ mm_nr_puds_init(mm);
mm->map_count = 0;
mm->locked_vm = 0;
mm->pinned_vm = 0;
@@ -878,6 +879,9 @@ static void check_mm(struct mm_struct *mm)
if (mm_nr_pmds(mm))
pr_alert("BUG: non-zero nr_pmds on freeing mm: %ld\n",
mm_nr_pmds(mm));
+ if (mm_nr_puds(mm))
+ pr_alert("BUG: non-zero nr_puds on freeing mm: %ld\n",
+ mm_nr_puds(mm));
#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
VM_BUG_ON_MM(mm->pmd_huge_pte, mm);