[PATCH] powerpc/mm/hugetlb: Don't panic if we don't find the default huge page size

[PATCH] powerpc/mm/hugetlb: Don't panic if we don't find the default huge page size

[Aneesh Kumar K.V]

generic hugetlbfs can handle that condition correctly. With HPAGE_SHIFT = 0
we get
[0.241333] hugetlbfs: disabling because there are no supported hugepage sizes

bash-4.2# echo 30 > /proc/sys/vm/nr_hugepages
bash: echo: write error: Operation not supported

Fixes: "powerpc: get hugetlbpage handling more generic"
Reported-by: Chris Smart <csmart@ozlabs.au.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/powerpc/mm/hugetlbpage.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 289df38fb7e0..e46bbd716832 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -852,9 +852,6 @@ static int __init hugetlbpage_init(void)
 	else if (mmu_psize_defs[MMU_PAGE_2M].shift)
 		HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_2M].shift;
 #endif
-	else
-		panic("%s: Unable to set default huge page size\n", __func__);
-
 	return 0;
 }
 
-- 
2.10.2

Re: [PATCH] powerpc/mm/hugetlb: Don't panic if we don't find the default huge page size

[Michael Neuling]

On Tue, 2016-12-13 at 19:34 +0530, Aneesh Kumar K.V wrote:
> generic hugetlbfs can handle that condition correctly. With HPAGE_SHIFT =
=3D 0
> we get
> [0.241333] hugetlbfs: disabling because there are no supported hugepage s=
izes
>=20
> bash-4.2# echo 30 > /proc/sys/vm/nr_hugepages
> bash: echo: write error: Operation not supported
>=20
> Fixes: "powerpc: get hugetlbpage handling more generic"
> Reported-by: Chris Smart <csmart@ozlabs.au.ibm.com>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

Acked-By: Michael Neuling <mikey@neuling.org>

> ---
> =C2=A0arch/powerpc/mm/hugetlbpage.c | 3 ---
> =C2=A01 file changed, 3 deletions(-)
>=20
> diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.=
c
> index 289df38fb7e0..e46bbd716832 100644
> --- a/arch/powerpc/mm/hugetlbpage.c
> +++ b/arch/powerpc/mm/hugetlbpage.c
> @@ -852,9 +852,6 @@ static int __init hugetlbpage_init(void)
> =C2=A0	else if (mmu_psize_defs[MMU_PAGE_2M].shift)
> =C2=A0		HPAGE_SHIFT =3D mmu_psize_defs[MMU_PAGE_2M].shift;
> =C2=A0#endif
> -	else
> -		panic("%s: Unable to set default huge page size\n",
> __func__);
> -
> =C2=A0	return 0;
> =C2=A0}
> =C2=A0

Re: [PATCH] powerpc/mm/hugetlb: Don't panic if we don't find the default huge page size

[Anshuman Khandual]

On 12/13/2016 07:34 PM, Aneesh Kumar K.V wrote:
> generic hugetlbfs can handle that condition correctly. With HPAGE_SHIFT = 0

Need to add some context here. "That condition" refers to something without
first mentioning it.

> we get
> [0.241333] hugetlbfs: disabling because there are no supported hugepage sizes
> 
> bash-4.2# echo 30 > /proc/sys/vm/nr_hugepages
> bash: echo: write error: Operation not supported
> 
> Fixes: "powerpc: get hugetlbpage handling more generic"

Dont we need the commit SHA for the "Fixes" header ?

Re: [PATCH] powerpc/mm/hugetlb: Don't panic if we don't find the default huge page size

[Aneesh Kumar K.V]

Anshuman Khandual <khandual@linux.vnet.ibm.com> writes:

> On 12/13/2016 07:34 PM, Aneesh Kumar K.V wrote:
>> generic hugetlbfs can handle that condition correctly. With HPAGE_SHIFT = 0
>
> Need to add some context here. "That condition" refers to something without
> first mentioning it.

It is the conditinal statement that gets removed as part of this patch.
The next line also explains what the generic code does for that condition.
>
>> we get
>> [0.241333] hugetlbfs: disabling because there are no supported hugepage sizes
>> 
>> bash-4.2# echo 30 > /proc/sys/vm/nr_hugepages
>> bash: echo: write error: Operation not supported
>> 
>> Fixes: "powerpc: get hugetlbpage handling more generic"
>
> Dont we need the commit SHA for the "Fixes" header ?

When I wrote the patch, the commit was not upstream. Hence i didn't had
an SHA1 to put there.

-aneesh

Re: powerpc/mm/hugetlb: Don't panic if we don't find the default huge page size

[Michael Ellerman]

On Tue, 2016-12-13 at 14:04:11 UTC, "Aneesh Kumar K.V" wrote:
> generic hugetlbfs can handle that condition correctly. With HPAGE_SHIFT = 0
> we get
> [0.241333] hugetlbfs: disabling because there are no supported hugepage sizes
> 
> bash-4.2# echo 30 > /proc/sys/vm/nr_hugepages
> bash: echo: write error: Operation not supported
> 
> Fixes: "powerpc: get hugetlbpage handling more generic"
> Reported-by: Chris Smart <csmart@ozlabs.au.ibm.com>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> Acked-By: Michael Neuling <mikey@neuling.org>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/ff8b85796dad5de869dc29903c9566

cheers