mm, slub: disable SYSFS support with CONFIG_SLUB_TINY

Currently SLUB enables its sysfs support depending unconditionally on
the general CONFIG_SYSFS setting. To reduce the configuration
combination space, make CONFIG_SLUB_TINY disable SLUB's sysfs support by
reusing the existing SLAB_SUPPORTS_SYSFS define. It is unlikely that
real tiny systems would combine CONFIG_SLUB_TINY with CONFIG_SYSFS, but
a randconfig might.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Christoph Lameter <cl@linux.com>

include/linux/slub_def.h

@@ -144,7 +144,7 @@ struct kmem_cache {
 	struct kmem_cache_node *node[MAX_NUMNODES];
 };
 
-#ifdef CONFIG_SYSFS
+#if defined(CONFIG_SYSFS) && !defined(CONFIG_SLUB_TINY)
 #define SLAB_SUPPORTS_SYSFS
 void sysfs_slab_unlink(struct kmem_cache *);
 void sysfs_slab_release(struct kmem_cache *);

mm/slub.c

@@ -298,7 +298,7 @@ struct track {
 
 enum track_item { TRACK_ALLOC, TRACK_FREE };
 
-#ifdef CONFIG_SYSFS
+#ifdef SLAB_SUPPORTS_SYSFS
 static int sysfs_slab_add(struct kmem_cache *);
 static int sysfs_slab_alias(struct kmem_cache *, const char *);
 #else
@@ -2935,7 +2935,7 @@ static noinline void free_debug_processing(
 }
 #endif /* CONFIG_SLUB_DEBUG */
 
-#if defined(CONFIG_SLUB_DEBUG) || defined(CONFIG_SYSFS)
+#if defined(CONFIG_SLUB_DEBUG) || defined(SLAB_SUPPORTS_SYSFS)
 static unsigned long count_partial(struct kmem_cache_node *n,
 					int (*get_count)(struct slab *))
 {
@@ -2949,7 +2949,7 @@ static unsigned long count_partial(struct kmem_cache_node *n,
 	spin_unlock_irqrestore(&n->list_lock, flags);
 	return x;
 }
-#endif /* CONFIG_SLUB_DEBUG || CONFIG_SYSFS */
+#endif /* CONFIG_SLUB_DEBUG || SLAB_SUPPORTS_SYSFS */
 
 static noinline void
 slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid)
@@ -4924,7 +4924,7 @@ int __kmem_cache_create(struct kmem_cache *s, slab_flags_t flags)
 	return 0;
 }
 
-#ifdef CONFIG_SYSFS
+#ifdef SLAB_SUPPORTS_SYSFS
 static int count_inuse(struct slab *slab)
 {
 	return slab->inuse;
@@ -5182,7 +5182,7 @@ static void process_slab(struct loc_track *t, struct kmem_cache *s,
 #endif  /* CONFIG_DEBUG_FS   */
 #endif	/* CONFIG_SLUB_DEBUG */
 
-#ifdef CONFIG_SYSFS
+#ifdef SLAB_SUPPORTS_SYSFS
 enum slab_stat_type {
 	SL_ALL,			/* All slabs */
 	SL_PARTIAL,		/* Only partially allocated slabs */
@@ -6060,7 +6060,7 @@ static int __init slab_sysfs_init(void)
 }
 
 __initcall(slab_sysfs_init);
-#endif /* CONFIG_SYSFS */
+#endif /* SLAB_SUPPORTS_SYSFS */
 
 #if defined(CONFIG_SLUB_DEBUG) && defined(CONFIG_DEBUG_FS)
 static int slab_debugfs_show(struct seq_file *seq, void *v)