mm/slub.c: wrap kmem_cache->cpu_partial in config CONFIG_SLUB_CPU_PARTIAL

kmem_cache->cpu_partial is just used when CONFIG_SLUB_CPU_PARTIAL is
set, so wrap it with config CONFIG_SLUB_CPU_PARTIAL will save some space
on 32bit arch.

This patch wraps kmem_cache->cpu_partial in config CONFIG_SLUB_CPU_PARTIAL
and wraps its sysfs too.

Link: http://lkml.kernel.org/r/20170502144533.10729-4-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 13 insertions, 0 deletions

diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index a3e9492fed02..cc0faf3a90be 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -86,7 +86,9 @@ struct kmem_cache {
         int size;               /* The size of an object including meta data */
         int object_size;        /* The size of an object without meta data */
         int offset;             /* Free pointer offset. */
+#ifdef CONFIG_SLUB_CPU_PARTIAL
         int cpu_partial;        /* Number of per cpu partial objects to keep around */
+#endif
         struct kmem_cache_order_objects oo;
 
         /* Allocation and freeing of slabs */
@@ -131,6 +133,17 @@ struct kmem_cache {
         struct kmem_cache_node *node[MAX_NUMNODES];
 };
 
+#ifdef CONFIG_SLUB_CPU_PARTIAL
+#define slub_cpu_partial(s)             ((s)->cpu_partial)
+#define slub_set_cpu_partial(s, n)              \
+({                                              \
+        slub_cpu_partial(s) = (n);              \
+})
+#else
+#define slub_cpu_partial(s)             (0)
+#define slub_set_cpu_partial(s, n)
+#endif // CONFIG_SLUB_CPU_PARTIAL
+
 #ifdef CONFIG_SYSFS
 #define SLAB_SUPPORTS_SYSFS
 void sysfs_slab_release(struct kmem_cache *);