| Message ID | 1375593061-11350-1-git-send-email-manjunath.goudar@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Sun, Aug 04, 2013 at 10:41:01AM +0530, 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); > Similar one. http://marc.info/?l=linux-mm&m=137532486405085&w=2 >Signed-off-by: Manjunath Goudar <manjunath.goudar@linaro.org> >Acked-by: Arnd Bergmann <arnd@linaro.org> >Cc: Deepak Saxena <dsaxena@linaro.org> >Cc: IWAMOTO Toshihiro <iwamoto@valinux.co.jp> >Cc: Hirokazu Takahashi <taka@valinux.co.jp> >Cc: Dave Hansen <haveblue@us.ibm.com> >Cc: linux-mm@kvack.org >Cc: Johannes Weiner <hannes@cmpxchg.org> >Cc: Michal Hocko <mhocko@suse.cz> >Cc: Balbir Singh <bsingharora@gmail.com> >Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> >--- > 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@kvack.org. For more info on Linux MM, >see: http://www.linux-mm.org/ . >Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
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@linaro.org> > Acked-by: Arnd Bergmann <arnd@linaro.org> > Cc: Deepak Saxena <dsaxena@linaro.org> > Cc: IWAMOTO Toshihiro <iwamoto@valinux.co.jp> > Cc: Hirokazu Takahashi <taka@valinux.co.jp> > Cc: Dave Hansen <haveblue@us.ibm.com> > Cc: linux-mm@kvack.org > Cc: Johannes Weiner <hannes@cmpxchg.org> > Cc: Michal Hocko <mhocko@suse.cz> > Cc: Balbir Singh <bsingharora@gmail.com> > Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> > --- > 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@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
On Mon 05-08-13 10:10:08, Manjunath Goudar wrote: > On 4 August 2013 13:24, Wanpeng Li <liwanp@linux.vnet.ibm.com> wrote: > > > On Sun, Aug 04, 2013 at 10:41:01AM +0530, 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); > > > > > > > Similar one. > > > > http://marc.info/?l=linux-mm&m=137532486405085&w=2 > > > In this patch MIGRATION config is not required MMU, because already CMA > config depends > on MMU and HAVE_MEMBLOCK if both are true then only selecting MIGRATION and > MEMORY_ISOLATION. No, I think it should be config MIGRATION that should depend on MMU explicitly because that is where the problem exists. It shouldn't rely on other configs to not select it automatically. The question is. Does CMA need to depend on MMU as well? Why? But please comment on the original thread instead.
On Mon 05-08-13 14:07:41, Manjunath Goudar wrote: > On 5 August 2013 13:02, Michal Hocko <mhocko@suse.cz> wrote: > > > On Mon 05-08-13 10:10:08, Manjunath Goudar wrote: > > > On 4 August 2013 13:24, Wanpeng Li <liwanp@linux.vnet.ibm.com> wrote: > > > > > > > On Sun, Aug 04, 2013 at 10:41:01AM +0530, 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); > > > > > > > > > > > > > Similar one. > > > > > > > > http://marc.info/?l=linux-mm&m=137532486405085&w=2 > > > > > > > > > In this patch MIGRATION config is not required MMU, because already CMA > > > config depends > > > on MMU and HAVE_MEMBLOCK if both are true then only selecting MIGRATION > > and > > > MEMORY_ISOLATION. > > > > No, I think it should be config MIGRATION that should depend on MMU > > explicitly because that is where the problem exists. It shouldn't rely > > on other configs to not select it automatically. > > > > Yes you are correct. > > > The question is. Does CMA need to depend on MMU as well? Why? > > But please comment on the original thread instead. > > > > I went through the mm/Kconfig, I think MMU dependence is not required > for CMA. OK, it turned out that it is needed in the end. Kcofing forces selects so CMA config would force MIGRATION even if that one depends on MMU.
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