On Sun 04-08-13 10:41:01, Manjunath Goudar wrote: > s patch adds a Kconfig dependency on an MMU being available before > CMA can be enabled. Without this patch, CMA can be enabled on an > MMU-less system which can lead to issues. This was discovered during > randconfig testing, in which CMA was enabled w/o MMU being enabled, > leading to the following error: > > CC mm/migrate.o > mm/migrate.c: In function ‘remove_migration_pte’: > mm/migrate.c:134:3: error: implicit declaration of function ‘pmd_trans_huge’ > [-Werror=implicit-function-declaration] > if (pmd_trans_huge(*pmd)) > ^ > mm/migrate.c:137:3: error: implicit declaration of function ‘pte_offset_map’ > [-Werror=implicit-function-declaration] > ptep = pte_offset_map(pmd, addr); This is a migration code but you are updating configuration for CMA which doesn't make much sense to me. I guess you wanted to disable migration for CMA instead? > Signed-off-by: Manjunath Goudar <manjunath.goudar@xxxxxxxxxx> > Acked-by: Arnd Bergmann <arnd@xxxxxxxxxx> > Cc: Deepak Saxena <dsaxena@xxxxxxxxxx> > Cc: IWAMOTO Toshihiro <iwamoto@xxxxxxxxxxxxx> > Cc: Hirokazu Takahashi <taka@xxxxxxxxxxxxx> > Cc: Dave Hansen <haveblue@xxxxxxxxxx> > Cc: linux-mm@xxxxxxxxx > Cc: Johannes Weiner <hannes@xxxxxxxxxxx> > Cc: Michal Hocko <mhocko@xxxxxxx> > Cc: Balbir Singh <bsingharora@xxxxxxxxx> > Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> > --- > mm/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/Kconfig b/mm/Kconfig > index 256bfd0..ad6b98e 100644 > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -522,7 +522,7 @@ config MEM_SOFT_DIRTY > > config CMA > bool "Contiguous Memory Allocator" > - depends on HAVE_MEMBLOCK > + depends on MMU && HAVE_MEMBLOCK > select MIGRATION > select MEMORY_ISOLATION > help > -- > 1.7.9.5 > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@xxxxxxxxx. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>