Re: [PATCH] sparc32: do not include swap.h from pgtable_32.h export struct mem_cgroup'

[Guenter Roeck <linux@roeck-us.net>]

On 08/04/2015 07:25 AM, Michal Hocko wrote:
> On Sat 01-08-15 20:02:20, Guenter Roeck wrote:
>> Hi,
>>
>> Commit b65390c6c2178f ("memcg: export struct mem_cgroup") causes several
>> build failures in -next (next-20150731) when trying to build
>> sparc32:allmodconfig.
>>
>> Below are some of the errors, as well as a bisect log.
>
> The following patch should take care of the mess. I've tested it with
> all{no,mod}config and defconfig. allyesconfig fails due to unrelated issue but
> make mm/ succeeds.
> ---
>>From 3ca0dfa93b1418bcb9a8dc2860bf93f095f72399 Mon Sep 17 00:00:00 2001
> From: Michal Hocko <mhocko@suse.com>
> Date: Tue, 4 Aug 2015 14:31:28 +0200
> Subject: [PATCH] sparc32: do not include swap.h from pgtable_32.h
>
> "memcg: export struct mem_cgroup" has added few includes into linux/memcontro.h
> which led to further header dependency issues as reported by Guenter Roeck:
>
> In file included from include/linux/highmem.h:7:0,
>                   from include/linux/bio.h:23,
>                   from include/linux/writeback.h:192,
>                   from include/linux/memcontrol.h:30,
>                   from include/linux/swap.h:8,
>                   from ./arch/sparc/include/asm/pgtable_32.h:17,
>                   from ./arch/sparc/include/asm/pgtable.h:6,
>                   from arch/sparc/kernel/traps_32.c:23:
> include/linux/mm.h: In function 'is_vmalloc_addr':
> include/linux/mm.h:371:17: error: 'VMALLOC_START' undeclared (first use in this function)
> include/linux/mm.h:371:17: note: each undeclared identifier is reported only once for each function it appears in
> include/linux/mm.h:371:41: error: 'VMALLOC_END' undeclared (first use in this function)
> include/linux/mm.h: In function 'maybe_mkwrite':
> include/linux/mm.h:556:3: error: implicit declaration of function 'pte_mkwrite'
>
> The issue is that pgtable_32.h depends on swap.h to get swap_entry_t but
> that goes all the way down to linux/mm.h which wants to have VMALLOC_*
> which is defined later in pgtable_32.h, though.
>
> swap_entry_t is defined in include/mm_types.h so it should be sufficient
> to include this header without more dependencies.
>
> Reported-by: Guenter Roeck <linux@roeck-us.net>
> Signed-off-by: Michal Hocko <mhocko@suse.com>

Nice and simple fix.

Compiled allmodconfig. Also ran through a number of qemu tests, all successful.

Building sparc32:SS-5:qemu_sparc_defconfig ... running ..... passed
Building sparc32:SS-20:qemu_sparc_defconfig ... running ..... passed
Building sparc32:SS-600MP:qemu_sparc_defconfig ... running ..... passed
Building sparc32:SS-5:qemu_sparc_smp_defconfig ... running ..... passed
Building sparc32:SS-20:qemu_sparc_smp_defconfig ... running ..... passed
Building sparc32:SS-600MP:qemu_sparc_smp_defconfig ... running ..... passed

Tested-by: Guenter Roeck <linux@roeck-us.net>

> ---
>   arch/sparc/include/asm/pgtable_32.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/sparc/include/asm/pgtable_32.h b/arch/sparc/include/asm/pgtable_32.h
> index f06b36a00a3b..91b963a887b7 100644
> --- a/arch/sparc/include/asm/pgtable_32.h
> +++ b/arch/sparc/include/asm/pgtable_32.h
> @@ -14,7 +14,7 @@
>   #include <asm-generic/4level-fixup.h>
>
>   #include <linux/spinlock.h>
> -#include <linux/swap.h>
> +#include <linux/mm_types.h>
>   #include <asm/types.h>
>   #include <asm/pgtsrmmu.h>
>   #include <asm/vaddrs.h>
>