From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx109.postini.com [74.125.245.109]) by kanga.kvack.org (Postfix) with SMTP id 3FB686B0031 for ; Sun, 4 Aug 2013 04:17:17 -0400 (EDT) Received: by mail-ob0-f181.google.com with SMTP id dn14so3784627obc.12 for ; Sun, 04 Aug 2013 01:17:16 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20130804080954.GB24005@dhcp22.suse.cz> References: <1375593061-11350-1-git-send-email-manjunath.goudar@linaro.org> <20130804080954.GB24005@dhcp22.suse.cz> Date: Sun, 4 Aug 2013 13:47:16 +0530 Message-ID: Subject: Re: [PATCH] MM: Make Contiguous Memory Allocator depends on MMU From: Manjunath Goudar Content-Type: multipart/alternative; boundary=90e6ba21219bd81fc104e31ad141 Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: linux-arm-kernel@lists.infradead.org, patches@linaro.org, arnd@linaro.org, dsaxena@linaro.org, linaro-kernel@lists.linaro.org, IWAMOTO Toshihiro , Hirokazu Takahashi , Dave Hansen , linux-mm@kvack.org, Johannes Weiner , Balbir Singh , KAMEZAWA Hiroyuki --90e6ba21219bd81fc104e31ad141 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable On 4 August 2013 13:39, Michal Hocko wrote: > 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 =91remove_migration_pte=92: > > mm/migrate.c:134:3: error: implicit declaration of function > =91pmd_trans_huge=92 > > [-Werror=3Dimplicit-function-declaration] > > if (pmd_trans_huge(*pmd)) > > ^ > > mm/migrate.c:137:3: error: implicit declaration of function > =91pte_offset_map=92 > > [-Werror=3Dimplicit-function-declaration] > > ptep =3D 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? > Yes you are right.Already Chen Gang has written similar patch. > > > Signed-off-by: Manjunath Goudar > > Acked-by: Arnd Bergmann > > Cc: Deepak Saxena > > Cc: IWAMOTO Toshihiro > > Cc: Hirokazu Takahashi > > Cc: Dave Hansen > > Cc: linux-mm@kvack.org > > Cc: Johannes Weiner > > Cc: Michal Hocko > > Cc: Balbir Singh > > Cc: KAMEZAWA Hiroyuki > > --- > > 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: email@kvack.org > > -- > Michal Hocko > SUSE Labs > Thanks Manjunath Goudar --90e6ba21219bd81fc104e31ad141 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable

On 4 August 2013 13:39, Michal Hocko <mhoc= ko@suse.cz> wrote:
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. =A0Without 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:
>
> =A0CC =A0 =A0 =A0mm/migrate.o
> mm/migrate.c: In function =91remove_migration_pte=92:
> mm/migrate.c:134:3: error: implicit declaration of function =91pmd_tra= ns_huge=92
> [-Werror=3Dimplicit-function-declaration]
> =A0 =A0if (pmd_trans_huge(*pmd))
> =A0 =A0^
> mm/migrate.c:137:3: error: implicit declaration of function =91pte_off= set_map=92
> [-Werror=3Dimplicit-function-declaration]
> =A0 =A0ptep =3D 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?

=A0Yes you are right.Already Chen Gang has written simila= r=A0patch.=A0

> Signed-off-by: Manjunath Goudar <manjunath.goudar@linaro.org>
> Acked-by: Arnd Bergmann <arnd@li= naro.org>
> Cc: Deepak Saxena <dsaxena@li= naro.org>
> Cc: IWAMOTO Toshihiro <iwa= moto@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@c= mpxchg.org>
> Cc: Michal Hocko <mhocko@suse.cz<= /a>>
> Cc: Balbir Singh <bsinghar= ora@gmail.com>
> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> ---
> =A0mm/Kconfig | =A0 =A02 +-
> =A01 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
>
> =A0config CMA
> =A0 =A0 =A0 bool "Contiguous Memory Allocator"
> - =A0 =A0 depends on HAVE_MEMBLOCK
> + =A0 =A0 depends on MMU && HAVE_MEMBLOCK
> =A0 =A0 =A0 select MIGRATION
> =A0 =A0 =A0 select MEMORY_ISOLATION
> =A0 =A0 =A0 help
> --
> 1.7.9.5
>
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in<= br> > the body to majordomo@kvack.org= . =A0For more info on Linux MM,
> see: http://www= .linux-mm.org/ .
> Don't email: <a href=3Dmailto:"dont@kvack.org"> emai= l@kvack.org </a>

--
Michal Hocko
SUSE Labs

Thanks
Manjunath Goudar=
--90e6ba21219bd81fc104e31ad141-- -- 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: email@kvack.org