[PATCH v1 0/5] Add update_mmu_tlb_range() to simplify code

[PATCH v1 0/5] Add update_mmu_tlb_range() to simplify code

[Bang Li]

This series of commits mainly adds the update_mmu_tlb_range() to
batch update tlb in an address range.

After the commit 19eaf44954df ("mm: thp: support allocation of anonymous
multi-size THP"), We may need to batch update tlb of a certain address
range by calling update_mmu_tlb() in a loop. Using the 
update_mmu_tlb_range(), we can simplify the code and possibly reduce the
execution of some unnecessary code in some architectures.

Bang Li (5):
  LoongArch: Add update_mmu_tlb_range()
  mips: Add update_mmu_tlb_range()
  riscv: Add update_mmu_tlb_range()
  xtensa: Add update_mmu_tlb_range()
  mm: Add update_mmu_tlb_range()

 arch/loongarch/include/asm/pgtable.h | 2 ++
 arch/mips/include/asm/pgtable.h      | 2 ++
 arch/riscv/include/asm/pgtable.h     | 2 ++
 arch/xtensa/include/asm/pgtable.h    | 2 ++
 arch/xtensa/mm/tlb.c                 | 6 ++++++
 include/linux/pgtable.h              | 5 +++++
 mm/memory.c                          | 4 +---
 7 files changed, 20 insertions(+), 3 deletions(-)

-- 
2.19.1.6.gb485710b

[PATCH v1 1/5] LoongArch: Add update_mmu_tlb_range()

[Bang Li]

Added update_mmu_tlb_range function, we can batch update tlb of an
address range.

Signed-off-by: Bang Li <libang.li@antgroup.com>
---
 arch/loongarch/include/asm/pgtable.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h
index af3acdf3481a..5ccc2a3a6f7a 100644
--- a/arch/loongarch/include/asm/pgtable.h
+++ b/arch/loongarch/include/asm/pgtable.h
@@ -469,6 +469,8 @@ static inline void update_mmu_cache_range(struct vm_fault *vmf,
 
 #define __HAVE_ARCH_UPDATE_MMU_TLB
 #define update_mmu_tlb	update_mmu_cache
+#define update_mmu_tlb_range(vma, addr, ptep, nr) \
+	update_mmu_cache_range(NULL, vma, addr, ptep, nr)
 
 static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
 			unsigned long address, pmd_t *pmdp)
-- 
2.19.1.6.gb485710b

[PATCH v1 2/5] mips: Add update_mmu_tlb_range()

[Bang Li]

Added update_mmu_tlb_range function, we can batch update tlb of an
address range.

Signed-off-by: Bang Li <libang.li@antgroup.com>
---
 arch/mips/include/asm/pgtable.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index e27a4c83c548..0891ad7d43b6 100644
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -596,6 +596,8 @@ static inline void update_mmu_cache_range(struct vm_fault *vmf,
 
 #define	__HAVE_ARCH_UPDATE_MMU_TLB
 #define update_mmu_tlb	update_mmu_cache
+#define update_mmu_tlb_range(vma, address, ptep, nr) \
+	update_mmu_cache_range(NULL, vma, address, ptep, nr)
 
 static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
 	unsigned long address, pmd_t *pmdp)
-- 
2.19.1.6.gb485710b

[PATCH v1 3/5] riscv: Add update_mmu_tlb_range()

[Bang Li]

Added update_mmu_tlb_range function, we can batch update tlb of an
address range.

Signed-off-by: Bang Li <libang.li@antgroup.com>
---
 arch/riscv/include/asm/pgtable.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index f2d5973a011b..d515a11a52cd 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -488,6 +488,8 @@ static inline void update_mmu_cache_range(struct vm_fault *vmf,
 
 #define __HAVE_ARCH_UPDATE_MMU_TLB
 #define update_mmu_tlb update_mmu_cache
+#define update_mmu_tlb_range(vma, addr, ptep, nr) \
+	update_mmu_cache_range(NULL, vma, addr, ptep, nr)
 
 static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
 		unsigned long address, pmd_t *pmdp)
-- 
2.19.1.6.gb485710b

[PATCH v1 4/5] xtensa: Add update_mmu_tlb_range()

[Bang Li]

Added update_mmu_tlb_range function, we can batch update tlb of an
address range.

Signed-off-by: Bang Li <libang.li@antgroup.com>
---
 arch/xtensa/include/asm/pgtable.h | 2 ++
 arch/xtensa/mm/tlb.c              | 6 ++++++
 2 files changed, 8 insertions(+)

diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h
index 9a7e5e57ee9a..50ccfc988256 100644
--- a/arch/xtensa/include/asm/pgtable.h
+++ b/arch/xtensa/include/asm/pgtable.h
@@ -412,6 +412,8 @@ typedef pte_t *pte_addr_t;
 
 void update_mmu_tlb(struct vm_area_struct *vma,
 		    unsigned long address, pte_t *ptep);
+void update_mmu_tlb_range(struct vm_area_struct *vma,
+			unsigned long address, pte_t *ptep, unsigned int nr);
 #define __HAVE_ARCH_UPDATE_MMU_TLB
 
 #endif /* !defined (__ASSEMBLY__) */
diff --git a/arch/xtensa/mm/tlb.c b/arch/xtensa/mm/tlb.c
index d8b60d6e50a8..05efba86b870 100644
--- a/arch/xtensa/mm/tlb.c
+++ b/arch/xtensa/mm/tlb.c
@@ -169,6 +169,12 @@ void update_mmu_tlb(struct vm_area_struct *vma,
 	local_flush_tlb_page(vma, address);
 }
 
+void update_mmu_tlb_range(struct vm_area_struct *vma,
+			unsigned long address, pte_t *ptep, unsigned int nr)
+{
+	local_flush_tlb_range(vma, address, address + PAGE_SIZE * nr);
+}
+
 #ifdef CONFIG_DEBUG_TLB_SANITY
 
 static unsigned get_pte_for_vaddr(unsigned vaddr)
-- 
2.19.1.6.gb485710b

[PATCH v1 5/5] mm: Add update_mmu_tlb_range()

[Bang Li]

After the commit 19eaf44954df ("mm: thp: support allocation of anonymous
multi-size THP"), it may need to batch update tlb of an address range
through the update_mmu_tlb function. We can simplify this operation by
adding the update_mmu_tlb_range function, which may also reduce the
execution of some unnecessary code in some architectures.

Signed-off-by: Bang Li <libang.li@antgroup.com>
---
 include/linux/pgtable.h | 5 +++++
 mm/memory.c             | 4 +---
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 18019f037bae..73411dfebf7a 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -734,6 +734,11 @@ static inline void update_mmu_tlb(struct vm_area_struct *vma,
 				unsigned long address, pte_t *ptep)
 {
 }
+
+static inline void update_mmu_tlb_range(struct vm_area_struct *vma,
+				unsigned long address, pte_t *ptep, unsigned int nr)
+{
+}
 #define __HAVE_ARCH_UPDATE_MMU_TLB
 #endif
 
diff --git a/mm/memory.c b/mm/memory.c
index 6647685fd3c4..1f0ca362b82a 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4396,7 +4396,6 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
 	vm_fault_t ret = 0;
 	int nr_pages = 1;
 	pte_t entry;
-	int i;
 
 	/* File mapping without ->vm_ops ? */
 	if (vma->vm_flags & VM_SHARED)
@@ -4465,8 +4464,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
 		update_mmu_tlb(vma, addr, vmf->pte);
 		goto release;
 	} else if (nr_pages > 1 && !pte_range_none(vmf->pte, nr_pages)) {
-		for (i = 0; i < nr_pages; i++)
-			update_mmu_tlb(vma, addr + PAGE_SIZE * i, vmf->pte + i);
+		update_mmu_tlb_range(vma, addr, vmf->pte, nr_pages);
 		goto release;
 	}
 
-- 
2.19.1.6.gb485710b

Re: [PATCH v1 5/5] mm: Add update_mmu_tlb_range()

[Lance Yang]

Hey Bang,

On Mon, Apr 29, 2024 at 6:36 PM Bang Li <libang.li@antgroup.com> wrote:
>
> After the commit 19eaf44954df ("mm: thp: support allocation of anonymous
> multi-size THP"), it may need to batch update tlb of an address range
> through the update_mmu_tlb function. We can simplify this operation by
> adding the update_mmu_tlb_range function, which may also reduce the
> execution of some unnecessary code in some architectures.
>
> Signed-off-by: Bang Li <libang.li@antgroup.com>
> ---
>  include/linux/pgtable.h | 5 +++++
>  mm/memory.c             | 4 +---
>  2 files changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
> index 18019f037bae..73411dfebf7a 100644
> --- a/include/linux/pgtable.h
> +++ b/include/linux/pgtable.h
> @@ -734,6 +734,11 @@ static inline void update_mmu_tlb(struct vm_area_struct *vma,
>                                 unsigned long address, pte_t *ptep)
>  {
>  }
> +
> +static inline void update_mmu_tlb_range(struct vm_area_struct *vma,
> +                               unsigned long address, pte_t *ptep, unsigned int nr)
> +{
> +}
>  #define __HAVE_ARCH_UPDATE_MMU_TLB
>  #endif

IMO, it might be better to use a separate definition to determine whether
update_mmu_tlb_range() is overridden by a specific architecture.

Thanks,
Lance

>
> diff --git a/mm/memory.c b/mm/memory.c
> index 6647685fd3c4..1f0ca362b82a 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -4396,7 +4396,6 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
>         vm_fault_t ret = 0;
>         int nr_pages = 1;
>         pte_t entry;
> -       int i;
>
>         /* File mapping without ->vm_ops ? */
>         if (vma->vm_flags & VM_SHARED)
> @@ -4465,8 +4464,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
>                 update_mmu_tlb(vma, addr, vmf->pte);
>                 goto release;
>         } else if (nr_pages > 1 && !pte_range_none(vmf->pte, nr_pages)) {
> -               for (i = 0; i < nr_pages; i++)
> -                       update_mmu_tlb(vma, addr + PAGE_SIZE * i, vmf->pte + i);
> +               update_mmu_tlb_range(vma, addr, vmf->pte, nr_pages);
>                 goto release;
>         }
>
> --
> 2.19.1.6.gb485710b
>

Re: [PATCH v1 5/5] mm: Add update_mmu_tlb_range()

[Bang Li]

Hey Lance,

Thanks for taking time to review!

On 2024/4/29 19:23, Lance Yang wrote:
> Hey Bang,
> 
> On Mon, Apr 29, 2024 at 6:36 PM Bang Li <libang.li@antgroup.com> wrote:
>>
>> After the commit 19eaf44954df ("mm: thp: support allocation of anonymous
>> multi-size THP"), it may need to batch update tlb of an address range
>> through the update_mmu_tlb function. We can simplify this operation by
>> adding the update_mmu_tlb_range function, which may also reduce the
>> execution of some unnecessary code in some architectures.
>>
>> Signed-off-by: Bang Li <libang.li@antgroup.com>
>> ---
>>   include/linux/pgtable.h | 5 +++++
>>   mm/memory.c             | 4 +---
>>   2 files changed, 6 insertions(+), 3 deletions(-)
>>
>> diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
>> index 18019f037bae..73411dfebf7a 100644
>> --- a/include/linux/pgtable.h
>> +++ b/include/linux/pgtable.h
>> @@ -734,6 +734,11 @@ static inline void update_mmu_tlb(struct vm_area_struct *vma,
>>                                  unsigned long address, pte_t *ptep)
>>   {
>>   }
>> +
>> +static inline void update_mmu_tlb_range(struct vm_area_struct *vma,
>> +                               unsigned long address, pte_t *ptep, unsigned int nr)
>> +{
>> +}
>>   #define __HAVE_ARCH_UPDATE_MMU_TLB
>>   #endif
> 
> IMO, it might be better to use a separate definition to determine whether
> update_mmu_tlb_range() is overridden by a specific architecture.

I have also considered this, and I will modify it in the next version.
thank you again for your review!

Thanks,
Bang

> 
> Thanks,
> Lance
> 
>>
>> diff --git a/mm/memory.c b/mm/memory.c
>> index 6647685fd3c4..1f0ca362b82a 100644
>> --- a/mm/memory.c
>> +++ b/mm/memory.c
>> @@ -4396,7 +4396,6 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
>>          vm_fault_t ret = 0;
>>          int nr_pages = 1;
>>          pte_t entry;
>> -       int i;
>>
>>          /* File mapping without ->vm_ops ? */
>>          if (vma->vm_flags & VM_SHARED)
>> @@ -4465,8 +4464,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
>>                  update_mmu_tlb(vma, addr, vmf->pte);
>>                  goto release;
>>          } else if (nr_pages > 1 && !pte_range_none(vmf->pte, nr_pages)) {
>> -               for (i = 0; i < nr_pages; i++)
>> -                       update_mmu_tlb(vma, addr + PAGE_SIZE * i, vmf->pte + i);
>> +               update_mmu_tlb_range(vma, addr, vmf->pte, nr_pages);
>>                  goto release;
>>          }
>>
>> --
>> 2.19.1.6.gb485710b
>>