From: KOSAKI Motohiro Current unevictable infrastructure code depend on MMU. Then, nommu build cause following error. mm/built-in.o(.text+0x1bb70): In function `truncate_complete_page': : undefined reference to `__clear_page_mlock' mm/built-in.o(.text+0x1ca90): In function `__invalidate_mapping_pages': : undefined reference to `__clear_page_mlock' mm/built-in.o(.text+0x1d29c): In function `invalidate_inode_pages2_range': : undefined reference to `__clear_page_mlock' So, adding dependency to Kconfig is better. Signed-off-by: KOSAKI Motohiro Cc: Lee Schermerhorn Cc: Rik van Riel Signed-off-by: Andrew Morton --- mm/Kconfig | 1 + 1 file changed, 1 insertion(+) diff -puN mm/Kconfig~unevictable-lru-infrastructure-nommu-fix mm/Kconfig --- a/mm/Kconfig~unevictable-lru-infrastructure-nommu-fix +++ a/mm/Kconfig @@ -209,6 +209,7 @@ config VIRT_TO_BUS config UNEVICTABLE_LRU bool "Add LRU list to track non-evictable pages" default y + depends on MMU help Keeps unevictable pages off of the active and inactive pageout lists, so kswapd will not waste CPU time or have its balancing _