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| author | Kirill A. Shutemov <kirill@shutemov.name> | 2014-12-11 02:44:36 +0300 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2016-06-03 18:30:36 +0300 |
| commit | 20b97db882d78bedb7c66c40008bbd3a0d7edabd (patch) | |
| tree | cc2fd1b0da6f84c2fd68ef17be2e1003a1f1afde /arch/x86 | |
| parent | aee24401991708c95e7b3189119fc917f1fc16b8 (diff) | |
| download | linux-20b97db882d78bedb7c66c40008bbd3a0d7edabd.tar.xz | |
mm: fix huge zero page accounting in smaps report
[ Upstream commit c164e038eee805147e95789dddb88ae3b3aca11c ]
As a small zero page, huge zero page should not be accounted in smaps
report as normal page.
For small pages we rely on vm_normal_page() to filter out zero page, but
vm_normal_page() is not designed to handle pmds. We only get here due
hackish cast pmd to pte in smaps_pte_range() -- pte and pmd format is not
necessary compatible on each and every architecture.
Let's add separate codepath to handle pmds. follow_trans_huge_pmd() will
detect huge zero page for us.
We would need pmd_dirty() helper to do this properly. The patch adds it
to THP-enabled architectures which don't yet have one.
[akpm@linux-foundation.org: use do_div to fix 32-bit build]
Signed-off-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Tested-by: Fengwei Yin <yfw.kernel@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/pgtable.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index aa97a070f09f..081d6f45e006 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -99,6 +99,11 @@ static inline int pte_young(pte_t pte) return pte_flags(pte) & _PAGE_ACCESSED; } +static inline int pmd_dirty(pmd_t pmd) +{ + return pmd_flags(pmd) & _PAGE_DIRTY; +} + static inline int pmd_young(pmd_t pmd) { return pmd_flags(pmd) & _PAGE_ACCESSED; |