[6/6] arm64/mm: Enable page table page accounting for user space
diff mbox series

Message ID 1548307220-19756-7-git-send-email-anshuman.khandual@arm.com
State New
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Series
  • arm64/mm: Enable accounting for page table pages
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Commit Message

Anshuman Khandual Jan. 24, 2019, 5:20 a.m. UTC
Page table pages created for user space processes must be accounted against
their memory control groups if initialized. This just introduces a helper
function pgtable_gfp_flags() which returns PGALLOC_GFP for all kernel page
table page allocations but adds __GFP_ACCOUNT for user page table pages.

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/arm64/include/asm/pgalloc.h | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

Comments

Will Deacon Feb. 14, 2019, 5:11 p.m. UTC | #1
On Thu, Jan 24, 2019 at 10:50:20AM +0530, Anshuman Khandual wrote:
> Page table pages created for user space processes must be accounted against
> their memory control groups if initialized. This just introduces a helper
> function pgtable_gfp_flags() which returns PGALLOC_GFP for all kernel page
> table page allocations but adds __GFP_ACCOUNT for user page table pages.
> 
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
>  arch/arm64/include/asm/pgalloc.h | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/include/asm/pgalloc.h b/arch/arm64/include/asm/pgalloc.h
> index 076764f..775cde9 100644
> --- a/arch/arm64/include/asm/pgalloc.h
> +++ b/arch/arm64/include/asm/pgalloc.h
> @@ -100,12 +100,22 @@ pte_alloc_one_kernel(struct mm_struct *mm)
>  	return (pte_t *)pte_alloc_one_virt(mm);
>  }
>  
> +static inline gfp_t pgtable_gfp_flags(struct mm_struct *mm)
> +{
> +	if (unlikely(mm == &init_mm))
> +		return PGALLOC_GFP;
> +	else
> +		return PGALLOC_GFP | __GFP_ACCOUNT;
> +}

Hmm, what about things like the efi mm?

Will
Anshuman Khandual Feb. 19, 2019, 4:49 a.m. UTC | #2
On 02/14/2019 10:41 PM, Will Deacon wrote:
> On Thu, Jan 24, 2019 at 10:50:20AM +0530, Anshuman Khandual wrote:
>> Page table pages created for user space processes must be accounted against
>> their memory control groups if initialized. This just introduces a helper
>> function pgtable_gfp_flags() which returns PGALLOC_GFP for all kernel page
>> table page allocations but adds __GFP_ACCOUNT for user page table pages.
>>
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>> ---
>>  arch/arm64/include/asm/pgalloc.h | 12 +++++++++++-
>>  1 file changed, 11 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/include/asm/pgalloc.h b/arch/arm64/include/asm/pgalloc.h
>> index 076764f..775cde9 100644
>> --- a/arch/arm64/include/asm/pgalloc.h
>> +++ b/arch/arm64/include/asm/pgalloc.h
>> @@ -100,12 +100,22 @@ pte_alloc_one_kernel(struct mm_struct *mm)
>>  	return (pte_t *)pte_alloc_one_virt(mm);
>>  }
>>  
>> +static inline gfp_t pgtable_gfp_flags(struct mm_struct *mm)
>> +{
>> +	if (unlikely(mm == &init_mm))
>> +		return PGALLOC_GFP;
>> +	else
>> +		return PGALLOC_GFP | __GFP_ACCOUNT;
>> +}
> 
> Hmm, what about things like the efi mm?


EFI mappings are created with

efi_virtmap_init() -> efi_create_mapping() -> create_pgd_mapping()

which calls into pgd_pgtable_alloc(). Sure will add check for efi_mm along
with init_mm not to use __GFP_ACCOUNT.

Patch
diff mbox series

diff --git a/arch/arm64/include/asm/pgalloc.h b/arch/arm64/include/asm/pgalloc.h
index 076764f..775cde9 100644
--- a/arch/arm64/include/asm/pgalloc.h
+++ b/arch/arm64/include/asm/pgalloc.h
@@ -100,12 +100,22 @@  pte_alloc_one_kernel(struct mm_struct *mm)
 	return (pte_t *)pte_alloc_one_virt(mm);
 }
 
+static inline gfp_t pgtable_gfp_flags(struct mm_struct *mm)
+{
+	if (unlikely(mm == &init_mm))
+		return PGALLOC_GFP;
+	else
+		return PGALLOC_GFP | __GFP_ACCOUNT;
+}
+
 static inline pgtable_t
 pte_alloc_one(struct mm_struct *mm)
 {
 	struct page *pte;
+	gfp_t gfp;
 
-	pte = alloc_pages(PGALLOC_GFP, 0);
+	gfp = pgtable_gfp_flags(mm);
+	pte = alloc_pages(gfp, 0);
 	if (!pte)
 		return NULL;
 	if (!pgtable_page_ctor(pte)) {