mm/slub.c: record final state of slub action in deactivate_slab()

If __cmpxchg_double_slab() fails and (l != m), current code records
transition states of slub action.

Update the action after __cmpxchg_double_slab() success to record the
final state.

[akpm@linux-foundation.org: more whitespace cleanup]
Link: http://lkml.kernel.org/r/20181107013119.3816-1-richard.weiyang@gmail.comSigned-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/slub.c

@@ -2131,26 +2131,15 @@ static void deactivate_slab(struct kmem_cache *s, struct page *page,
 	}
 
 	if (l != m) {
-
 		if (l == M_PARTIAL)
-
 			remove_partial(n, page);
-
 		else if (l == M_FULL)
-
 			remove_full(s, n, page);
 
-		if (m == M_PARTIAL) {
-
+		if (m == M_PARTIAL)
 			add_partial(n, page, tail);
-			stat(s, tail);
-
-		} else if (m == M_FULL) {
-
-			stat(s, DEACTIVATE_FULL);
+		else if (m == M_FULL)
 			add_full(s, n, page);
-
-		}
 	}
 
 	l = m;
@@ -2163,7 +2152,11 @@ static void deactivate_slab(struct kmem_cache *s, struct page *page,
 	if (lock)
 		spin_unlock(&n->list_lock);
 
-	if (m == M_FREE) {
+	if (m == M_PARTIAL)
+		stat(s, tail);
+	else if (m == M_FULL)
+		stat(s, DEACTIVATE_FULL);
+	else if (m == M_FREE) {
 		stat(s, DEACTIVATE_EMPTY);
 		discard_slab(s, page);
 		stat(s, FREE_SLAB);