* [RFC PATCH] powerpc/mm/hugetlb: Add support for 1G huge pages
@ 2017-04-04 14:03 Aneesh Kumar K.V
2017-04-05 5:35 ` Anshuman Khandual
0 siblings, 1 reply; 3+ messages in thread
From: Aneesh Kumar K.V @ 2017-04-04 14:03 UTC (permalink / raw)
To: benh, paulus, mpe; +Cc: linuxppc-dev, Aneesh Kumar K.V
This patch adds support for gigantic pages in ppc64. We also updates
gigantic_page_supported helper such that arch can override it.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/book3s/64/hugetlb.h | 9 +++++++++
arch/powerpc/mm/hugetlbpage.c | 7 +++++--
arch/powerpc/platforms/Kconfig.cputype | 1 +
mm/hugetlb.c | 4 ++++
4 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/hugetlb.h b/arch/powerpc/include/asm/book3s/64/hugetlb.h
index 6666cd366596..a994d069fdaf 100644
--- a/arch/powerpc/include/asm/book3s/64/hugetlb.h
+++ b/arch/powerpc/include/asm/book3s/64/hugetlb.h
@@ -50,4 +50,13 @@ static inline pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
else
return entry;
}
+
+#define gigantic_page_supported gigantic_page_supported
+static inline bool gigantic_page_supported(void)
+{
+ if (radix_enabled())
+ return true;
+ return false;
+}
+
#endif
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index a4f33de4008e..80f6d2ed551a 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -763,8 +763,11 @@ static int __init add_huge_page_size(unsigned long long size)
* Hash: 16M and 16G
*/
if (radix_enabled()) {
- if (mmu_psize != MMU_PAGE_2M)
- return -EINVAL;
+ if (mmu_psize != MMU_PAGE_2M) {
+ if (cpu_has_feature(CPU_FTR_POWER9_DD1) ||
+ (mmu_psize != MMU_PAGE_1G))
+ return -EINVAL;
+ }
} else {
if (mmu_psize != MMU_PAGE_16M && mmu_psize != MMU_PAGE_16G)
return -EINVAL;
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index a7c0c1fafe68..382c3dd86d6d 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -343,6 +343,7 @@ config PPC_STD_MMU_64
config PPC_RADIX_MMU
bool "Radix MMU Support"
depends on PPC_BOOK3S_64
+ select ARCH_HAS_GIGANTIC_PAGE
default y
help
Enable support for the Power ISA 3.0 Radix style MMU. Currently this
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 3d0aab9ee80d..2c090189f314 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1158,7 +1158,11 @@ static int alloc_fresh_gigantic_page(struct hstate *h,
return 0;
}
+#ifndef gigantic_page_supported
static inline bool gigantic_page_supported(void) { return true; }
+#define gigantic_page_supported gigantic_page_supported
+#endif
+
#else
static inline bool gigantic_page_supported(void) { return false; }
static inline void free_gigantic_page(struct page *page, unsigned int order) { }
--
2.7.4
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [RFC PATCH] powerpc/mm/hugetlb: Add support for 1G huge pages
2017-04-04 14:03 [RFC PATCH] powerpc/mm/hugetlb: Add support for 1G huge pages Aneesh Kumar K.V
@ 2017-04-05 5:35 ` Anshuman Khandual
2017-04-05 6:33 ` Aneesh Kumar K.V
0 siblings, 1 reply; 3+ messages in thread
From: Anshuman Khandual @ 2017-04-05 5:35 UTC (permalink / raw)
To: Aneesh Kumar K.V, benh, paulus, mpe; +Cc: linuxppc-dev
On 04/04/2017 07:33 PM, Aneesh Kumar K.V wrote:
> This patch adds support for gigantic pages in ppc64. We also updates
> gigantic_page_supported helper such that arch can override it.
Seems like only radix based 1GB is considered as gigantic page in this
implementation. What about the existing 16GB pages support ? IIUC they
are still supported currently as gigantic pages (as defined in generic
HugeTLB) if the platform gives us reserved memory areas during boot.
Can you explain how this is going to be different ?
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> ---
> arch/powerpc/include/asm/book3s/64/hugetlb.h | 9 +++++++++
> arch/powerpc/mm/hugetlbpage.c | 7 +++++--
> arch/powerpc/platforms/Kconfig.cputype | 1 +
> mm/hugetlb.c | 4 ++++
> 4 files changed, 19 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/book3s/64/hugetlb.h b/arch/powerpc/include/asm/book3s/64/hugetlb.h
> index 6666cd366596..a994d069fdaf 100644
> --- a/arch/powerpc/include/asm/book3s/64/hugetlb.h
> +++ b/arch/powerpc/include/asm/book3s/64/hugetlb.h
> @@ -50,4 +50,13 @@ static inline pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
> else
> return entry;
> }
> +
> +#define gigantic_page_supported gigantic_page_supported
> +static inline bool gigantic_page_supported(void)
> +{
> + if (radix_enabled())
> + return true;
> + return false;
> +}
POWER8 (non radix MMU) cannot have 16GB gigantic HugeTLB pages ?
> +
> #endif
> diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
> index a4f33de4008e..80f6d2ed551a 100644
> --- a/arch/powerpc/mm/hugetlbpage.c
> +++ b/arch/powerpc/mm/hugetlbpage.c
> @@ -763,8 +763,11 @@ static int __init add_huge_page_size(unsigned long long size)
> * Hash: 16M and 16G
> */
> if (radix_enabled()) {
> - if (mmu_psize != MMU_PAGE_2M)
> - return -EINVAL;
> + if (mmu_psize != MMU_PAGE_2M) {
> + if (cpu_has_feature(CPU_FTR_POWER9_DD1) ||
> + (mmu_psize != MMU_PAGE_1G))
> + return -EINVAL;
> + }
The comment above this code block needs to be updated as well for
this new page size addition. I understand that this code block
was added to protect against wrong device tree supplied page size
values but wondering dont we require one such check for normal page
sizes as well (non HugeTLB) ? But anyways, thats a different topic.
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [RFC PATCH] powerpc/mm/hugetlb: Add support for 1G huge pages
2017-04-05 5:35 ` Anshuman Khandual
@ 2017-04-05 6:33 ` Aneesh Kumar K.V
0 siblings, 0 replies; 3+ messages in thread
From: Aneesh Kumar K.V @ 2017-04-05 6:33 UTC (permalink / raw)
To: Anshuman Khandual, benh, paulus, mpe; +Cc: linuxppc-dev
On Wednesday 05 April 2017 11:05 AM, Anshuman Khandual wrote:
> On 04/04/2017 07:33 PM, Aneesh Kumar K.V wrote:
>> This patch adds support for gigantic pages in ppc64. We also updates
>> gigantic_page_supported helper such that arch can override it.
>
> Seems like only radix based 1GB is considered as gigantic page in this
> implementation. What about the existing 16GB pages support ? IIUC they
> are still supported currently as gigantic pages (as defined in generic
> HugeTLB) if the platform gives us reserved memory areas during boot.
> Can you explain how this is going to be different ?
>
>>
>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
>> ---
>> arch/powerpc/include/asm/book3s/64/hugetlb.h | 9 +++++++++
>> arch/powerpc/mm/hugetlbpage.c | 7 +++++--
>> arch/powerpc/platforms/Kconfig.cputype | 1 +
>> mm/hugetlb.c | 4 ++++
>> 4 files changed, 19 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/book3s/64/hugetlb.h b/arch/powerpc/include/asm/book3s/64/hugetlb.h
>> index 6666cd366596..a994d069fdaf 100644
>> --- a/arch/powerpc/include/asm/book3s/64/hugetlb.h
>> +++ b/arch/powerpc/include/asm/book3s/64/hugetlb.h
>> @@ -50,4 +50,13 @@ static inline pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
>> else
>> return entry;
>> }
>> +
>> +#define gigantic_page_supported gigantic_page_supported
>> +static inline bool gigantic_page_supported(void)
>> +{
>> + if (radix_enabled())
>> + return true;
>> + return false;
>> +}
>
> POWER8 (non radix MMU) cannot have 16GB gigantic HugeTLB pages ?
that helper determines whether we can do gigantic page allocation at
runtime. I doubt we can do that for 16GB pages. Hence this is only
enabled for 1G radix config
-aneesh
^ permalink raw reply [flat|nested] 3+ messages in thread
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2017-04-04 14:03 [RFC PATCH] powerpc/mm/hugetlb: Add support for 1G huge pages Aneesh Kumar K.V
2017-04-05 5:35 ` Anshuman Khandual
2017-04-05 6:33 ` Aneesh Kumar K.V
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