Merge branch 'slub-tiny-v1r6' into slab/for-next

Merge my series [1] to deprecate the SLOB allocator.
- Renames CONFIG_SLOB to CONFIG_SLOB_DEPRECATED with deprecation notice.
- The recommended replacement is CONFIG_SLUB, optionally with the new
  CONFIG_SLUB_TINY tweaks for systems with 16MB or less RAM.
- Use cases that stopped working with CONFIG_SLUB_TINY instead of SLOB
  should be reported to linux-mm@kvack.org and slab maintainers,
  otherwise SLOB will be removed in few cycles.

[1] https://lore.kernel.org/all/20221121171202.22080-1-vbabka@suse.cz/

mm/slab.h

@@ -217,8 +217,6 @@ struct kmem_cache {
 	unsigned int size;	/* The aligned/padded/added on size  */
 	unsigned int align;	/* Alignment as calculated */
 	slab_flags_t flags;	/* Active flags on the slab */
-	unsigned int useroffset;/* Usercopy region offset */
-	unsigned int usersize;	/* Usercopy region size */
 	const char *name;	/* Slab name for sysfs */
 	int refcount;		/* Use counter */
 	void (*ctor)(void *);	/* Called on object slot creation */