mm: disable split page table lock for !MMU
There's no reason to enable split page table lock if don't have page
tables.
It also triggers build error at least on ARM since we don't define
pmd_page() for !MMU.
In file included from arch/arm/kernel/asm-offsets.c:14:0:
include/linux/mm.h: In function 'pte_lockptr':
include/linux/mm.h:1392:2: error: implicit declaration of function 'pmd_page' [-Werror=implicit-function-declaration]
include/linux/mm.h:1392:2: warning: passing argument 1 of 'ptlock_ptr' makes pointer from integer without a cast [enabled by default]
include/linux/mm.h:1384:27: note: expected 'struct page *' but argument is of type 'int'
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/Kconfig b/mm/Kconfig
index 2888024..37fbe1e 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -216,6 +216,7 @@
#
config SPLIT_PTLOCK_CPUS
int
+ default "999999" if !MMU
default "999999" if ARM && !CPU_CACHE_VIPT
default "999999" if PARISC && !PA20
default "4"