slab allocators: Remove obsolete SLAB_MUST_HWCACHE_ALIGN

This patch was recently posted to lkml and acked by Pekka.

The flag SLAB_MUST_HWCACHE_ALIGN is

1. Never checked by SLAB at all.

2. A duplicate of SLAB_HWCACHE_ALIGN for SLUB

3. Fulfills the role of SLAB_HWCACHE_ALIGN for SLOB.

The only remaining use is in sparc64 and ppc64 and their use there
reflects some earlier role that the slab flag once may have had. If
its specified then SLAB_HWCACHE_ALIGN is also specified.

The flag is confusing, inconsistent and has no purpose.

Remove it.

Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 3 deletions

diff --git a/mm/slub.c b/mm/slub.c
index 3904002bdb35..79940e98e5e6 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1496,7 +1496,7 @@ static unsigned long calculate_alignment(unsigned long flags,
          * specified alignment though. If that is greater
          * then use it.
          */
-        if ((flags & (SLAB_MUST_HWCACHE_ALIGN | SLAB_HWCACHE_ALIGN)) &&
+        if ((flags & SLAB_HWCACHE_ALIGN) &&
                         size > L1_CACHE_BYTES / 2)
                 return max_t(unsigned long, align, L1_CACHE_BYTES);
 
@@ -3142,8 +3142,7 @@ SLAB_ATTR(reclaim_account);
 
 static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf)
 {
-        return sprintf(buf, "%d\n", !!(s->flags &
-                (SLAB_HWCACHE_ALIGN|SLAB_MUST_HWCACHE_ALIGN)));
+        return sprintf(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN));
 }
 SLAB_ATTR_RO(hwcache_align);