On Mon 05-08-13 16:46:14, Chen Gang F T wrote: > On 08/05/2013 03:32 PM, Michal Hocko wrote: > > On Thu 01-08-13 10:39:57, Chen Gang wrote: > >> MIGRATION need depend on MMU, or allmodconfig for sh architecture which > >> without MMU will be fail for compiling. > >> > >> The related 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:149:2: error: implicit declaration of function 'is_swap_pte' [-Werror=implicit-function-declaration] > >> if (!is_swap_pte(pte)) > >> ^ > >> ... > >> > >> > >> Signed-off-by: Chen Gang <gang.chen@xxxxxxxxxxx> > >> --- > >> mm/Kconfig | 4 ++-- > >> 1 files changed, 2 insertions(+), 2 deletions(-) > >> > >> diff --git a/mm/Kconfig b/mm/Kconfig > >> index 256bfd0..e847f19 100644 > >> --- a/mm/Kconfig > >> +++ b/mm/Kconfig > >> @@ -245,7 +245,7 @@ config COMPACTION > >> config MIGRATION > >> bool "Page migration" > >> def_bool y > >> - depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION || CMA > >> + depends on (NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION || CMA) && MMU > >> help > >> Allows the migration of the physical location of pages of processes > >> while the virtual addresses are not changed. This is useful in > >> @@ -522,7 +522,7 @@ config MEM_SOFT_DIRTY > >> > >> config CMA > >> bool "Contiguous Memory Allocator" > >> - depends on HAVE_MEMBLOCK > >> + depends on HAVE_MEMBLOCK && MMU > > > > Why CMA has to depend on MMU as well? The MIGRATION part should be > > sufficient. > > > > MIGRATION need depend on MMU, when NOMMU, if select CMA, it will select > MIGRATION by force. Ohh, I wasn't aware of this Kcofing limitation. You are right then and CMA needs a dependency as well. > e.g. for allmodconfig with sh architecture, if we only let MIGRATION > depend on MMU, not let CMA depend on MMU, it will report the warning > below: > > scripts/kconfig/conf --allmodconfig Kconfig > warning: (COMPACTION && CMA) selects MIGRATION which has unmet direct dependencies ((NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION || CMA) && MMU) > > And for the final config file, MIGRATION is still enabled, although MMU > is not defined. > > > >> select MIGRATION > >> select MEMORY_ISOLATION > >> help > > > > Thanks. > -- > Chen Gang > > -- > 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>