2024-02-09 05:42:48

by Anshuman Khandual

Subject: [PATCH] mm/hugetlb: Move page order check inside hugetlb_cma_reserve()

All platforms could benefit from page order check against MAX_PAGE_ORDER
before allocating a CMA area for gigantic hugetlb pages. Let's move this
check from individual platforms to generic hugetlb.

Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Anshuman Khandual <[email protected]>
---
This applies on v6.8-rc3

arch/arm64/mm/hugetlbpage.c | 7 -------
arch/powerpc/mm/hugetlbpage.c | 4 +---
mm/hugetlb.c | 7 +++++++
3 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index 8116ac599f80..6720ec8d50e7 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -45,13 +45,6 @@ void __init arm64_hugetlb_cma_reserve(void)
else
order = CONT_PMD_SHIFT - PAGE_SHIFT;

- /*
- * HugeTLB CMA reservation is required for gigantic
- * huge pages which could not be allocated via the
- * page allocator. Just warn if there is any change
- * breaking this assumption.
- */
- WARN_ON(order <= MAX_PAGE_ORDER);
hugetlb_cma_reserve(order);
}
#endif /* CONFIG_CMA */
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 0a540b37aab6..16557d008eef 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -614,8 +614,6 @@ void __init gigantic_hugetlb_cma_reserve(void)
*/
order = mmu_psize_to_shift(MMU_PAGE_16G) - PAGE_SHIFT;

- if (order) {
- VM_WARN_ON(order <= MAX_PAGE_ORDER);
+ if (order)
hugetlb_cma_reserve(order);
- }
}
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index cf9c9b2906ea..345b3524df35 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -7699,6 +7699,13 @@ void __init hugetlb_cma_reserve(int order)
bool node_specific_cma_alloc = false;
int nid;

+ /*
+ * HugeTLB CMA reservation is required for gigantic
+ * huge pages which could not be allocated via the
+ * page allocator. Just warn if there is any change
+ * breaking this assumption.
+ */
+ VM_WARN_ON(order <= MAX_PAGE_ORDER);
cma_reserve_called = true;

if (!hugetlb_cma_size)
--
2.25.1

2024-02-09 06:51:26

by Jane Chu

Subject: Re: [PATCH] mm/hugetlb: Move page order check inside hugetlb_cma_reserve()

On 2/8/2024 9:42 PM, Anshuman Khandual wrote:

> All platforms could benefit from page order check against MAX_PAGE_ORDER
> before allocating a CMA area for gigantic hugetlb pages. Let's move this
> check from individual platforms to generic hugetlb.
>
> Cc: Catalin Marinas <[email protected]>
> Cc: Will Deacon <[email protected]>
> Cc: Michael Ellerman <[email protected]>
> Cc: Nicholas Piggin <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Signed-off-by: Anshuman Khandual <[email protected]>
> ---
> This applies on v6.8-rc3
>
> arch/arm64/mm/hugetlbpage.c | 7 -------
> arch/powerpc/mm/hugetlbpage.c | 4 +---
> mm/hugetlb.c | 7 +++++++
> 3 files changed, 8 insertions(+), 10 deletions(-)
>
> diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
> index 8116ac599f80..6720ec8d50e7 100644
> --- a/arch/arm64/mm/hugetlbpage.c
> +++ b/arch/arm64/mm/hugetlbpage.c
> @@ -45,13 +45,6 @@ void __init arm64_hugetlb_cma_reserve(void)
> else
> order = CONT_PMD_SHIFT - PAGE_SHIFT;
>
> - /*
> - * HugeTLB CMA reservation is required for gigantic
> - * huge pages which could not be allocated via the
> - * page allocator. Just warn if there is any change
> - * breaking this assumption.
> - */
> - WARN_ON(order <= MAX_PAGE_ORDER);
> hugetlb_cma_reserve(order);
> }
> #endif /* CONFIG_CMA */
> diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
> index 0a540b37aab6..16557d008eef 100644
> --- a/arch/powerpc/mm/hugetlbpage.c
> +++ b/arch/powerpc/mm/hugetlbpage.c
> @@ -614,8 +614,6 @@ void __init gigantic_hugetlb_cma_reserve(void)
> */
> order = mmu_psize_to_shift(MMU_PAGE_16G) - PAGE_SHIFT;
>
> - if (order) {
> - VM_WARN_ON(order <= MAX_PAGE_ORDER);
> + if (order)
> hugetlb_cma_reserve(order);
> - }
> }
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index cf9c9b2906ea..345b3524df35 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -7699,6 +7699,13 @@ void __init hugetlb_cma_reserve(int order)
> bool node_specific_cma_alloc = false;
> int nid;
>
> + /*
> + * HugeTLB CMA reservation is required for gigantic
> + * huge pages which could not be allocated via the
> + * page allocator. Just warn if there is any change
> + * breaking this assumption.
> + */
> + VM_WARN_ON(order <= MAX_PAGE_ORDER);
> cma_reserve_called = true;
>
> if (!hugetlb_cma_size)

Looks straight forward to me.

Reviewed-by: Jane Chu <[email protected]>

2024-02-12 14:19:31

by David Hildenbrand

Subject: Re: [PATCH] mm/hugetlb: Move page order check inside hugetlb_cma_reserve()

On 09.02.24 06:42, Anshuman Khandual wrote:
> All platforms could benefit from page order check against MAX_PAGE_ORDER
> before allocating a CMA area for gigantic hugetlb pages. Let's move this
> check from individual platforms to generic hugetlb.
>
> Cc: Catalin Marinas <[email protected]>
> Cc: Will Deacon <[email protected]>
> Cc: Michael Ellerman <[email protected]>
> Cc: Nicholas Piggin <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Signed-off-by: Anshuman Khandual <[email protected]>
> ---
> This applies on v6.8-rc3
>
> arch/arm64/mm/hugetlbpage.c | 7 -------
> arch/powerpc/mm/hugetlbpage.c | 4 +---
> mm/hugetlb.c | 7 +++++++
> 3 files changed, 8 insertions(+), 10 deletions(-)
>
> diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
> index 8116ac599f80..6720ec8d50e7 100644
> --- a/arch/arm64/mm/hugetlbpage.c
> +++ b/arch/arm64/mm/hugetlbpage.c
> @@ -45,13 +45,6 @@ void __init arm64_hugetlb_cma_reserve(void)
> else
> order = CONT_PMD_SHIFT - PAGE_SHIFT;
>
> - /*
> - * HugeTLB CMA reservation is required for gigantic
> - * huge pages which could not be allocated via the
> - * page allocator. Just warn if there is any change
> - * breaking this assumption.
> - */
> - WARN_ON(order <= MAX_PAGE_ORDER);
> hugetlb_cma_reserve(order);
> }
> #endif /* CONFIG_CMA */
> diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
> index 0a540b37aab6..16557d008eef 100644
> --- a/arch/powerpc/mm/hugetlbpage.c
> +++ b/arch/powerpc/mm/hugetlbpage.c
> @@ -614,8 +614,6 @@ void __init gigantic_hugetlb_cma_reserve(void)
> */
> order = mmu_psize_to_shift(MMU_PAGE_16G) - PAGE_SHIFT;
>
> - if (order) {
> - VM_WARN_ON(order <= MAX_PAGE_ORDER);
> + if (order)
> hugetlb_cma_reserve(order);
> - }
> }
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index cf9c9b2906ea..345b3524df35 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -7699,6 +7699,13 @@ void __init hugetlb_cma_reserve(int order)
> bool node_specific_cma_alloc = false;
> int nid;
>
> + /*
> + * HugeTLB CMA reservation is required for gigantic
> + * huge pages which could not be allocated via the
> + * page allocator. Just warn if there is any change
> + * breaking this assumption.
> + */
> + VM_WARN_ON(order <= MAX_PAGE_ORDER);
> cma_reserve_called = true;
>
> if (!hugetlb_cma_size)

Reviewed-by: David Hildenbrand <[email protected]>

--
Cheers,

David / dhildenb