mm/slab_common: commonize slab merge logic

Slab merge is good feature to reduce fragmentation.  Now, it is only
applied to SLUB, but, it would be good to apply it to SLAB.  This patch is
preparation step to apply slab merge to SLAB by commonizing slab merge
logic.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 5 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index d9a452e8fb9b..a126a31dde02 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -3158,6 +3158,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 
         slram=          [HW,MTD]
 
+        slab_nomerge    [MM]
+                        Disable merging of slabs with similar size. May be
+                        necessary if there is some reason to distinguish
+                        allocs to different slabs. Debug options disable
+                        merging on their own.
+                        For more information see Documentation/vm/slub.txt.
+
         slab_max_order= [MM, SLAB]
                         Determines the maximum allowed order for slabs.
                         A high setting may cause OOMs due to memory
@@ -3193,11 +3200,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                         For more information see Documentation/vm/slub.txt.
 
         slub_nomerge    [MM, SLUB]
-                        Disable merging of slabs with similar size. May be
-                        necessary if there is some reason to distinguish
-                        allocs to different slabs. Debug options disable
-                        merging on their own.
-                        For more information see Documentation/vm/slub.txt.
+                        Same with slab_nomerge. This is supported for legacy.
+                        See slab_nomerge for more information.
 
         smart2=         [HW]
                         Format: <io1>[,<io2>[,...,<io8>]]