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| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2013-11-21 14:32:09 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-11-21 16:42:28 -0800 |
| commit | c283610e44ec4ccc412dde8b71cf297ed9515f2f (patch) | |
| tree | dd3c83db8dabefbeb3733cd428cced7c62602beb /Documentation/vm | |
| parent | 3a72660b07d86d60457ca32080b1ce8c2b628ee2 (diff) | |
| download | linux-c283610e44ec4ccc412dde8b71cf297ed9515f2f.tar.gz linux-c283610e44ec4ccc412dde8b71cf297ed9515f2f.tar.bz2 linux-c283610e44ec4ccc412dde8b71cf297ed9515f2f.zip | |
x86, mm: do not leak page->ptl for pmd page tables
There are two code paths how page with pmd page table can be freed:
pmd_free() and pmd_free_tlb().
I've missed the second one and didn't add page table destructor call
there. It leads to leak of page->ptl for pmd page tables, if
dynamically allocated page->ptl is in use.
The patch adds the missed destructor and modifies documentation
accordingly.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Andrey Vagin <avagin@openvz.org>
Tested-by: Andrey Vagin <avagin@openvz.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/vm')
| -rw-r--r-- | Documentation/vm/split_page_table_lock | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/Documentation/vm/split_page_table_lock b/Documentation/vm/split_page_table_lock index 7521d367f21d..6dea4fd5c961 100644 --- a/Documentation/vm/split_page_table_lock +++ b/Documentation/vm/split_page_table_lock @@ -63,9 +63,9 @@ levels. PMD split lock enabling requires pgtable_pmd_page_ctor() call on PMD table allocation and pgtable_pmd_page_dtor() on freeing. -Allocation usually happens in pmd_alloc_one(), freeing in pmd_free(), but -make sure you cover all PMD table allocation / freeing paths: i.e X86_PAE -preallocate few PMDs on pgd_alloc(). +Allocation usually happens in pmd_alloc_one(), freeing in pmd_free() and +pmd_free_tlb(), but make sure you cover all PMD table allocation / freeing +paths: i.e X86_PAE preallocate few PMDs on pgd_alloc(). With everything in place you can set CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK. |