slub: Switch per cpu partial page support off for debugging

Eric saw an issue with accounting of slabs during validation. Its not
possible to determine accurately how many per cpu partial slabs exist at
any time so this switches off per cpu partial pages during debug.

Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
diff --git a/mm/slub.c b/mm/slub.c
index ed3334d..4056d29 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3028,7 +3028,9 @@
 	 *    per node list when we run out of per cpu objects. We only fetch 50%
 	 *    to keep some capacity around for frees.
 	 */
-	if (s->size >= PAGE_SIZE)
+	if (kmem_cache_debug(s))
+		s->cpu_partial = 0;
+	else if (s->size >= PAGE_SIZE)
 		s->cpu_partial = 2;
 	else if (s->size >= 1024)
 		s->cpu_partial = 6;