page-flags: define behavior SL*B-related flags on compound pages

SL*B uses compound pages and marks head pages with PG_slab.
__SetPageSlab() and __ClearPageSlab() are never called for tail pages.

The same situation with PG_slob_free in SLOB allocator.

PF_NO_TAIL is appropriate for these flags.

Signed-off-by: Kirill A. Shutemov <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Steve Capper <[email protected]>
Cc: "Aneesh Kumar K.V" <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Jerome Marchand <[email protected]>
Cc: Jérôme Glisse <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 88a3bcba57d666af2dd363c5bb57d035f941a3ef..29d8805aaa23c416beb6c3db2b9725e46ed99c1a 100644 (file)
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -266,7 +266,8 @@ PAGEFLAG(Dirty, dirty, PF_HEAD) TESTSCFLAG(Dirty, dirty, PF_HEAD)
 PAGEFLAG(LRU, lru, PF_HEAD) __CLEARPAGEFLAG(LRU, lru, PF_HEAD)
 PAGEFLAG(Active, active, PF_HEAD) __CLEARPAGEFLAG(Active, active, PF_HEAD)
        TESTCLEARFLAG(Active, active, PF_HEAD)
-__PAGEFLAG(Slab, slab, PF_ANY)
+__PAGEFLAG(Slab, slab, PF_NO_TAIL)
+__PAGEFLAG(SlobFree, slob_free, PF_NO_TAIL)
 PAGEFLAG(Checked, checked, PF_NO_COMPOUND)        /* Used by some filesystems */
 PAGEFLAG(Pinned, pinned, PF_ANY) TESTSCFLAG(Pinned, pinned, PF_ANY)    /* Xen */
 PAGEFLAG(SavePinned, savepinned, PF_ANY);                      /* Xen */
@@ -276,8 +277,6 @@ PAGEFLAG(SwapBacked, swapbacked, PF_ANY)
        __CLEARPAGEFLAG(SwapBacked, swapbacked, PF_ANY)
        __SETPAGEFLAG(SwapBacked, swapbacked, PF_ANY)
 
-__PAGEFLAG(SlobFree, slob_free, PF_ANY)
-
 /*
  * Private page markings that may be used by the filesystem that owns the page
  * for its own purposes.