SLUB: add CONFIG_SLUB_DEBUG

CONFIG_SLUB_DEBUG can be used to switch off the debugging and sysfs components
of SLUB.  Thus SLUB will be able to replace SLOB.  SLUB can arrange objects in
a denser way than SLOB and the code size should be minimal without debugging
and sysfs support.

Note that CONFIG_SLUB_DEBUG is materially different from CONFIG_SLAB_DEBUG.
CONFIG_SLAB_DEBUG is used to enable slab debugging in SLAB.  SLUB enables
debugging via a boot parameter.  SLUB debug code should always be present.

CONFIG_SLUB_DEBUG can be modified in the embedded config section.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/init/Kconfig b/init/Kconfig
index d0edf42..da6a91c 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -504,6 +504,15 @@
 	  on EMBEDDED systems.  /proc/vmstat will only show page counts
 	  if VM event counters are disabled.
 
+config SLUB_DEBUG
+	default y
+	bool "Enable SLUB debugging support" if EMBEDDED
+	help
+	  SLUB has extensive debug support features. Disabling these can
+	  result in significant savings in code size. This also disables
+	  SLUB sysfs support. /sys/slab will not exist and there will be
+	  no support for cache validation etc.
+
 choice
 	prompt "Choose SLAB allocator"
 	default SLAB