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| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2016-06-24 23:49:51 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-06-25 02:23:52 +0200 |
| commit | c17b1f42594eb71b8d3eb5a6dfc907a7eb88a51d (patch) | |
| tree | b24f8fa0aaa1537ea9965e22ca6b9c9a030d2be5 /mm/sparse-vmemmap.c | |
| parent | Revert "mm: disable fault around on emulated access bit architecture" (diff) | |
| download | linux-c17b1f42594eb71b8d3eb5a6dfc907a7eb88a51d.tar.xz linux-c17b1f42594eb71b8d3eb5a6dfc907a7eb88a51d.zip | |
hugetlb: fix nr_pmds accounting with shared page tables
We account HugeTLB's shared page table to all processes who share it.
The accounting happens during huge_pmd_share().
If somebody populates pud entry under us, we should decrease pagetable's
refcount and decrease nr_pmds of the process.
By mistake, I increase nr_pmds again in this case. :-/ It will lead to
"BUG: non-zero nr_pmds on freeing mm: 2" on process' exit.
Let's fix this by increasing nr_pmds only when we're sure that the page
table will be used.
Link: http://lkml.kernel.org/r/20160617122506.GC6534@node.shutemov.name
Fixes: dc6c9a35b66b ("mm: account pmd page tables to the process")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: zhongjiang <zhongjiang@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/sparse-vmemmap.c')
0 files changed, 0 insertions, 0 deletions