mm.h: Fix noMMU breakage

mm.h: Fix noMMU breakage

[Michal Simek]

Hi,

all noMMU systems are broken that's why I would like to add
this patch (or any similar/better) to mainline ASAP. 
For more information please look at patch description.

Can you give me some ACKs?

Who is responsible for this mm patch? Andrew?

Thanks,
Michal

[PATCH] mm: System without MMU do not need pte_mkwrite

[Michal Simek]

The patch "thp: export maybe_mkwrite"
(sha1 14fd403f2146f740942d78af4e0ee59396ad8eab)
break systems without MMU.

Error log:
  CC      arch/microblaze/mm/init.o
In file included from include/linux/mman.h:14,
                 from arch/microblaze/mm/consistent.c:24:
include/linux/mm.h: In function 'maybe_mkwrite':
include/linux/mm.h:482: error: implicit declaration of function 'pte_mkwrite'
include/linux/mm.h:482: error: incompatible types in assignment

Signed-off-by: Michal Simek <monstr@monstr.eu>
CC: Andrea Arcangeli <aarcange@redhat.com>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Rik van Riel <riel@redhat.com>
CC: Ingo Molnar <mingo@elte.hu>
---
 include/linux/mm.h |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 956a355..f6385fc 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -470,6 +470,7 @@ static inline void set_compound_order(struct page *page, unsigned long order)
 	page[1].lru.prev = (void *)order;
 }
 
+#ifdef CONFIG_MMU
 /*
  * Do pte_mkwrite, but only if the vma says VM_WRITE.  We do this when
  * servicing faults for write access.  In the normal case, do always want
@@ -482,6 +483,7 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
 		pte = pte_mkwrite(pte);
 	return pte;
 }
+#endif
 
 /*
  * Multiple processes may "see" the same page. E.g. for untouched
-- 
1.5.5.6

Re: [PATCH] mm: System without MMU do not need pte_mkwrite

[Rik van Riel]

On 01/21/2011 02:49 AM, Michal Simek wrote:
> The patch "thp: export maybe_mkwrite"
> (sha1 14fd403f2146f740942d78af4e0ee59396ad8eab)
> break systems without MMU.
>
> Error log:
>    CC      arch/microblaze/mm/init.o
> In file included from include/linux/mman.h:14,
>                   from arch/microblaze/mm/consistent.c:24:
> include/linux/mm.h: In function 'maybe_mkwrite':
> include/linux/mm.h:482: error: implicit declaration of function 'pte_mkwrite'
> include/linux/mm.h:482: error: incompatible types in assignment
>
> Signed-off-by: Michal Simek<monstr@monstr.eu>
> CC: Andrea Arcangeli<aarcange@redhat.com>
> CC: Linus Torvalds<torvalds@linux-foundation.org>
> CC: Andrew Morton<akpm@linux-foundation.org>
> CC: Rik van Riel<riel@redhat.com>
> CC: Ingo Molnar<mingo@elte.hu>

Reviewed-by: Rik van Riel <riel@redhat.com>

-- 
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