[PATCH -next] mm: Drop unnecessary include file

[PATCH -next] mm: Drop unnecessary include file

[Guenter Roeck]

Commmit e9be930fa6b5 ("mm: fix vm-scalability regression in cgroup-aware
workingset code") adds '#include <linux/mm.h>' to
include/linux/memcontrol.h. This results in the following build error
when building hexagon images.

In file included from ./include/linux/memcontrol.h:32:0,
                 from ./include/linux/swap.h:8,
		 from ./arch/hexagon/include/asm/pgtable.h:27,
		 from mm/init-mm.c:9:
./include/linux/mm.h:322:2: error: unknown type name 'pmd_t'
./include/linux/mm.h:353:7: error: unknown type name 'pmd_t'
./include/linux/mm.h:414:30: error: unknown type name 'pmd_t'

The include file does not appear to be necessary, so just drop it.

Fixes: e9be930fa6b5 ("mm: fix vm-scalability regression in cgroup-aware workingset code")
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
Build tested with all architectures. No related build failures observed.

 include/linux/memcontrol.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 2cf30455b25f..5d8ca6e02e39 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -29,7 +29,6 @@
 #include <linux/mmzone.h>
 #include <linux/writeback.h>
 #include <linux/page-flags.h>
-#include <linux/mm.h>
 
 struct mem_cgroup;
 struct page;
-- 
2.5.0

Re: [PATCH -next] mm: Drop unnecessary include file

[Michal Hocko]

On Sat 23-07-16 22:50:08, Guenter Roeck wrote:
> Commmit e9be930fa6b5 ("mm: fix vm-scalability regression in cgroup-aware
> workingset code") adds '#include <linux/mm.h>' to

This sha is linux-next specific. This means it is unstable and shouldn't
be referred to in a commit message. The patch you are fixing is sitting
in the Andrew's tree as
mm-fix-vm-scalability-regression-in-cgroup-aware-workingset-code.patch

I guess it can be just folded into the above patch.

> include/linux/memcontrol.h. This results in the following build error
> when building hexagon images.
> 
> In file included from ./include/linux/memcontrol.h:32:0,
>                  from ./include/linux/swap.h:8,
> 		 from ./arch/hexagon/include/asm/pgtable.h:27,
> 		 from mm/init-mm.c:9:
> ./include/linux/mm.h:322:2: error: unknown type name 'pmd_t'
> ./include/linux/mm.h:353:7: error: unknown type name 'pmd_t'
> ./include/linux/mm.h:414:30: error: unknown type name 'pmd_t'
> 
> The include file does not appear to be necessary, so just drop it.

Yes that seems to be really the case. I have just run it through my
compile testing scripts and it works fine. Unfortunatelly my all arch
cross build test doesn't include hexagon.

> Fixes: e9be930fa6b5 ("mm: fix vm-scalability regression in cgroup-aware workingset code")
> Cc: Johannes Weiner <hannes@cmpxchg.org>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Acked-by: Michal Hocko <mhocko@suse.com>

Thanks!

> ---
> Build tested with all architectures. No related build failures observed.
> 
>  include/linux/memcontrol.h | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index 2cf30455b25f..5d8ca6e02e39 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -29,7 +29,6 @@
>  #include <linux/mmzone.h>
>  #include <linux/writeback.h>
>  #include <linux/page-flags.h>
> -#include <linux/mm.h>
>  
>  struct mem_cgroup;
>  struct page;
> -- 
> 2.5.0

-- 
Michal Hocko
SUSE Labs

Re: [PATCH -next] mm: Drop unnecessary include file

[Johannes Weiner]

On Sat, Jul 23, 2016 at 10:50:08PM -0700, Guenter Roeck wrote:
> Commmit e9be930fa6b5 ("mm: fix vm-scalability regression in cgroup-aware
> workingset code") adds '#include <linux/mm.h>' to
> include/linux/memcontrol.h. This results in the following build error
> when building hexagon images.
> 
> In file included from ./include/linux/memcontrol.h:32:0,
>                  from ./include/linux/swap.h:8,
> 		 from ./arch/hexagon/include/asm/pgtable.h:27,
> 		 from mm/init-mm.c:9:
> ./include/linux/mm.h:322:2: error: unknown type name 'pmd_t'
> ./include/linux/mm.h:353:7: error: unknown type name 'pmd_t'
> ./include/linux/mm.h:414:30: error: unknown type name 'pmd_t'
> 
> The include file does not appear to be necessary, so just drop it.
> 
> Fixes: e9be930fa6b5 ("mm: fix vm-scalability regression in cgroup-aware workingset code")
> Cc: Johannes Weiner <hannes@cmpxchg.org>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>

It was needed because mem_cgroup_zone_zoneinfo() used zone_to_nid().
Mel's nodelru patches have since renamed it to mem_cgroup_nodeinfo()
and dropped the zone_to_nid() reference, that's why it's no longer
necessary.

Acked-by: Johannes Weiner <hannes@cmpxchg.org>

[ I'd put it in after the nodelru patches, though, to maintain
  bisectability on x86 over hexagon. ]