diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2016-01-15 16:52:03 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-01-15 17:56:32 -0800 |
| commit | 822cdd1152265d87fcfc974e06c3b68f762987fd (patch) | |
| tree | 7d90a95f44143ae0a51ef736e6db3404d01a9faa /include/linux/page-flags.h | |
| parent | d2998c4de2937b964ea63aa2c08183f28462d532 (diff) | |
page-flags: look at head page if the flag is encoded in page->mapping
PageAnon() and PageKsm() look at lower bits of page->mapping to check if
the page is Anon or KSM. page->mapping can be overloaded in tail pages.
Let's always look at head page to avoid false-positives.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/page-flags.h')
| -rw-r--r-- | include/linux/page-flags.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 818fa39538a9..190f1915a097 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -176,7 +176,7 @@ static inline int PageCompound(struct page *page) #define PF_NO_TAIL(page, enforce) ({ \ VM_BUG_ON_PGFLAGS(enforce && PageTail(page), page); \ compound_head(page);}) -#define PF_NO_COMPOUND(page, enforce) ({ \ +#define PF_NO_COMPOUND(page, enforce) ({ \ VM_BUG_ON_PGFLAGS(enforce && PageCompound(page), page); \ page;}) @@ -381,6 +381,7 @@ PAGEFLAG(Idle, idle, PF_ANY) static inline int PageAnon(struct page *page) { + page = compound_head(page); return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0; } @@ -393,6 +394,7 @@ static inline int PageAnon(struct page *page) */ static inline int PageKsm(struct page *page) { + page = compound_head(page); return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM); } |