[PATCH] Correct build warnings with CONFIG_TRANSPARENT_HUGEPAGE disabled

[PATCH] Correct build warnings with CONFIG_TRANSPARENT_HUGEPAGE disabled

[Nathan Fontenot]

Building with CONFIG_TRANSPARENT_HUGEPAGE disabled causes the following
build wearnings;

powerpc/arch/powerpc/include/asm/mmu-hash64.h: In function ‘__hash_page_thp’:
powerpc/arch/powerpc/include/asm/mmu-hash64.h:354: warning: no return statement in function returning non-void

This patch adds a return -1 to the static inline for __hash_page_thp()
to correct the warnings.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/mmu-hash64.h |    1 +
 1 file changed, 1 insertion(+)

Index: powerpc/arch/powerpc/include/asm/mmu-hash64.h
===================================================================
--- powerpc.orig/arch/powerpc/include/asm/mmu-hash64.h	2013-06-24 07:54:08.000000000 -0500
+++ powerpc/arch/powerpc/include/asm/mmu-hash64.h	2013-06-24 08:07:56.000000000 -0500
@@ -351,6 +351,7 @@
 				  int ssize, unsigned int psize)
 {
 	BUG();
+	return -1;
 }
 #endif
 extern void hash_failure_debug(unsigned long ea, unsigned long access,

Re: [PATCH] Correct build warnings with CONFIG_TRANSPARENT_HUGEPAGE disabled

[Aneesh Kumar K.V]

Nathan Fontenot <nfont@linux.vnet.ibm.com> writes:

> Building with CONFIG_TRANSPARENT_HUGEPAGE disabled causes the following
> build wearnings;
>
> powerpc/arch/powerpc/include/asm/mmu-hash64.h: In function =E2=80=98__has=
h_page_thp=E2=80=99:
> powerpc/arch/powerpc/include/asm/mmu-hash64.h:354: warning: no return sta=
tement in function returning non-void
>
> This patch adds a return -1 to the static inline for __hash_page_thp()
> to correct the warnings.
>
> Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

Wondering why i am not finding this

[root@llmp24l02 thp]# make arch/powerpc/mm/hash_utils_64.o
....
.....
  CC      arch/powerpc/mm/hash_utils_64.o
[root@llmp24l02 thp]# grep TRANSPARENT_HUGEPAGE .config
CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE=3Dy
# CONFIG_TRANSPARENT_HUGEPAGE is not set
[root@llmp24l02 thp]#=20
[root@llmp24l02 thp]# gcc --version
gcc (GCC) 4.7.2 20121109 (Red Hat 4.7.2-8)
Copyright (C) 2012 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.


> ---
>  arch/powerpc/include/asm/mmu-hash64.h |    1 +
>  1 file changed, 1 insertion(+)
>
> Index: powerpc/arch/powerpc/include/asm/mmu-hash64.h
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> --- powerpc.orig/arch/powerpc/include/asm/mmu-hash64.h	2013-06-24 07:54:0=
8.000000000 -0500
> +++ powerpc/arch/powerpc/include/asm/mmu-hash64.h	2013-06-24 08:07:56.000=
000000 -0500
> @@ -351,6 +351,7 @@
>  				  int ssize, unsigned int psize)
>  {
>  	BUG();
> +	return -1;
>  }
>  #endif
>  extern void hash_failure_debug(unsigned long ea, unsigned long access,

Re: [PATCH] Correct build warnings with CONFIG_TRANSPARENT_HUGEPAGE disabled

[Aneesh Kumar K.V]

"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> writes:

> Nathan Fontenot <nfont@linux.vnet.ibm.com> writes:
>
>> Building with CONFIG_TRANSPARENT_HUGEPAGE disabled causes the following
>> build wearnings;
>>
>> powerpc/arch/powerpc/include/asm/mmu-hash64.h: In function =E2=80=98__ha=
sh_page_thp=E2=80=99:
>> powerpc/arch/powerpc/include/asm/mmu-hash64.h:354: warning: no return st=
atement in function returning non-void
>>
>> This patch adds a return -1 to the static inline for __hash_page_thp()
>> to correct the warnings.
>>
>> Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
>
> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
>
> Wondering why i am not finding this
>
> [root@llmp24l02 thp]# make arch/powerpc/mm/hash_utils_64.o
> ....
> .....
>   CC      arch/powerpc/mm/hash_utils_64.o
> [root@llmp24l02 thp]# grep TRANSPARENT_HUGEPAGE .config
> CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE=3Dy
> # CONFIG_TRANSPARENT_HUGEPAGE is not set
> [root@llmp24l02 thp]#=20
> [root@llmp24l02 thp]# gcc --version
> gcc (GCC) 4.7.2 20121109 (Red Hat 4.7.2-8)
> Copyright (C) 2012 Free Software Foundation, Inc.
> This is free software; see the source for copying conditions.  There is NO
> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOS=
E.
>
>

new compilers have __builtin_unreachable in BUG. That is why it didn't
trigger for me.=20

new compiler:
_____________
static inline __attribute__((always_inline)) __attribute__((no_instrument_f=
unction)) int __hash_page_thp(unsigned long ea, unsigned long access,
      unsigned long vsid, pmd_t *pmdp,
      unsigned long trap, int local,
      int ssize, unsigned int psize)
{
 do { __asm__ __volatile__( "1:	twi 31,0,0\n" ".section __bug_table,\"a\"\n=
" "2:\t" ".llong" " " "1b, %0\n" "\t.short %1, %2\n" ".org 2b+%3\n" ".previ=
ous\n" : : "i" ("/home/opensource/sources/kernels/linux-powerpc/arch/powerp=
c/include/asm/mmu-hash64.h"), "i" (353), "i" (0), "i" (sizeof(struct bug_en=
try))); __builtin_unreachable(); } while (0);
}

failure:
__________
static inline __attribute__((always_inline)) __attribute__((no_instrument_f=
unction)) int __hash_page_thp(unsigned long ea, unsigned long access,
      unsigned long vsid, pmd_t *pmdp,
      unsigned long trap, int local,
      int ssize, unsigned int psize)
{
 do { __asm__ __volatile__( "1: twi 31,0,0\n" ".section __bug_table,\"a\"\n=
" "2:\t" ".llong" " " "1b, %0\n" "\t.short %1, %2\n" ".org 2b+%3\n" ".previ=
ous\n" : : "i" ("/home/nfont/src/powerpc/arch/powerpc/include/asm/mmu-hash6=
4.h"), "i" (353), "i" (0), "i" (sizeof(struct bug_entry))); do { } while (1=
); } while (0);
}


-aneesh

RE: [PATCH] Correct build warnings with CONFIG_TRANSPARENT_HUGEPAGE disabled

[David Laight]

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