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.

NO_TAIL is appropriate for these flags.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.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: 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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index bdb0d0e226c4272230001a5f599fe58f67ae3fa1..d41c63b566b899703281b779bd396ae36ca87f20 100644 (file)
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -279,7 +279,8 @@ PAGEFLAG(Dirty, dirty, HEAD) TESTSCFLAG(Dirty, dirty, HEAD)
 PAGEFLAG(LRU, lru, HEAD) __CLEARPAGEFLAG(LRU, lru, HEAD)
 PAGEFLAG(Active, active, HEAD) __CLEARPAGEFLAG(Active, active, HEAD)
        TESTCLEARFLAG(Active, active, HEAD)
-__PAGEFLAG(Slab, slab, ANY)
+__PAGEFLAG(Slab, slab, NO_TAIL)
+__PAGEFLAG(SlobFree, slob_free, NO_TAIL)
 PAGEFLAG(Checked, checked, NO_COMPOUND) /* Used by some filesystems */
 PAGEFLAG(Pinned, pinned, ANY) TESTSCFLAG(Pinned, pinned, ANY)  /* Xen */
 PAGEFLAG(SavePinned, savepinned, ANY);                 /* Xen */
@@ -289,8 +290,6 @@ PAGEFLAG(SwapBacked, swapbacked, ANY)
        __CLEARPAGEFLAG(SwapBacked, swapbacked, ANY)
        __SETPAGEFLAG(SwapBacked, swapbacked, ANY)
 
-__PAGEFLAG(SlobFree, slob_free, ANY)
-
 /*
  * Private page markings that may be used by the filesystem that owns the page
  * for its own purposes.