slab: make create_kmalloc_cache() work with 32-bit sizes

KMALLOC_MAX_CACHE_SIZE is 32-bit so is the largest kmalloc cache size.

Christoph said:
:
: Ok SLABs maximum allocation size is limited to 32M (see
: include/linux/slab.h:
:
: #define KMALLOC_SHIFT_HIGH      ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
:                                 (MAX_ORDER + PAGE_SHIFT - 1) : 25)
:
: And SLUB/SLOB pass all larger requests to the page allocator anyways.

Link: http://lkml.kernel.org/r/20180305200730.15812-4-adobriyan@gmail.com
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: 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/slab.h

@@ -77,7 +77,7 @@ extern struct kmem_cache *kmem_cache;
 /* A table of kmalloc cache names and sizes */
 extern const struct kmalloc_info_struct {
 	const char *name;
-	unsigned long size;
+	unsigned int size;
 } kmalloc_info[];
 
 #ifndef CONFIG_SLOB
@@ -93,9 +93,9 @@ struct kmem_cache *kmalloc_slab(size_t, gfp_t);
 /* Functions provided by the slab allocators */
 int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags);
 
-extern struct kmem_cache *create_kmalloc_cache(const char *name, size_t size,
-			slab_flags_t flags, size_t useroffset,
-			size_t usersize);
+struct kmem_cache *create_kmalloc_cache(const char *name, unsigned int size,
+			slab_flags_t flags, unsigned int useroffset,
+			unsigned int usersize);
 extern void create_boot_cache(struct kmem_cache *, const char *name,
 			size_t size, slab_flags_t flags, size_t useroffset,
 			size_t usersize);

mm/slab_common.c

@@ -939,9 +939,9 @@ void __init create_boot_cache(struct kmem_cache *s, const char *name, size_t siz
 	s->refcount = -1;	/* Exempt from merging for now */
 }
 
-struct kmem_cache *__init create_kmalloc_cache(const char *name, size_t size,
-				slab_flags_t flags, size_t useroffset,
-				size_t usersize)
+struct kmem_cache *__init create_kmalloc_cache(const char *name,
+		unsigned int size, slab_flags_t flags,
+		unsigned int useroffset, unsigned int usersize)
 {
 	struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);