[PATCH] lib/rhashtable: make build optional

[Aristeu Rozanski <aris@redhat.com>]

From: Aristeu Rozanski <arozansk@redhat.com>

rhashtable currently is built unconditionally:
	text    data     bss     dec     hex filename
	9158    2008    5264   16430    402e lib/rhashtable.o
	9158    2008    5264   16430    402e (TOTALS)

and it's used by netlink (which currently can't be optionally built if
CONFIG_NET is enabled) and netfilter_hash. This patch is useful for
situations in which memory footprint is a concern and networking is not
enabled.

Cc: David S. Miller <davem@davemloft.net>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Ying Xue <ying.xue@windriver.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Aristeu Rozanski <arozansk@redhat.com>
---
 lib/Kconfig  | 6 ++++++
 lib/Makefile | 4 +++-
 net/Kconfig  | 1 +
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/lib/Kconfig b/lib/Kconfig
index 108196c..d6b8879 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -369,6 +369,12 @@ config ASSOCIATIVE_ARRAY
 
 	  for more information.
 
+config RHASH_TABLE
+	bool "Resizable hash table"
+	default y
+	help
+	  Resizable, scalable and concurrent hash table implementation.
+
 config HAS_IOMEM
 	boolean
 	depends on !NO_IOMEM
diff --git a/lib/Makefile b/lib/Makefile
index 53fd120..43d29ff 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -26,7 +26,7 @@ obj-y += bcd.o div64.o sort.o parser.o debug_locks.o random32.o \
 	 bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \
 	 gcd.o lcm.o list_sort.o uuid.o iovec.o clz_ctz.o \
 	 bsearch.o find_last_bit.o find_next_bit.o llist.o memweight.o kfifo.o \
-	 percpu-refcount.o percpu_ida.o hash.o rhashtable.o
+	 percpu-refcount.o percpu_ida.o hash.o
 obj-y += string_helpers.o
 obj-$(CONFIG_TEST_STRING_HELPERS) += test-string_helpers.o
 obj-y += kstrtox.o
@@ -155,6 +155,8 @@ obj-$(CONFIG_GENERIC_NET_UTILS) += net_utils.o
 
 obj-$(CONFIG_STMP_DEVICE) += stmp_device.o
 
+obj-$(CONFIG_RHASH_TABLE) += rhashtable.o
+
 libfdt_files = fdt.o fdt_ro.o fdt_wip.o fdt_rw.o fdt_sw.o fdt_strerror.o \
 	       fdt_empty_tree.o
 $(foreach file, $(libfdt_files), \
diff --git a/net/Kconfig b/net/Kconfig
index 99815b5..d376630 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -7,6 +7,7 @@ menuconfig NET
 	select NLATTR
 	select GENERIC_NET_UTILS
 	select BPF
+	select RHASH_TABLE
 	---help---
 	  Unless you really know what you are doing, you should say Y here.
 	  The reason is that some programs need kernel networking support even
-- 
1.8.3.1