[PATCH v2] mm: thp: support "THPeligible" semantics for mTHP with anonymous shmem

[PATCH v2] mm: thp: support "THPeligible" semantics for mTHP with anonymous shmem

[Bang Li]

After the commit 7fb1b252afb5 ("mm: shmem: add mTHP support for
anonymous shmem"), we can configure different policies through
the multi-size THP sysfs interface for anonymous shmem. But
currently "THPeligible" indicates only whether the mapping is
eligible for allocating THP-pages as well as the THP is PMD
mappable or not for anonymous shmem, we need to support semantics
for mTHP with anonymous shmem similar to those for mTHP with
anonymous memory.

Signed-off-by: Bang Li <libang.li@antgroup.com>
---
Changes since v1 [1]:
 - Put anonymous shmem mthp related logic into
   thp_vma_allowable_orders() (per David)

[1] https://lore.kernel.org/linux-mm/20240628104926.34209-1-libang.li@antgroup.com/
---
 include/linux/huge_mm.h | 11 +++++++++++
 mm/huge_memory.c        | 13 +++++++++----
 mm/shmem.c              |  9 +--------
 3 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 212cca384d7e..f87136f38aa1 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -267,6 +267,10 @@ unsigned long thp_vma_allowable_orders(struct vm_area_struct *vma,
 	return __thp_vma_allowable_orders(vma, vm_flags, tva_flags, orders);
 }
 
+unsigned long shmem_allowable_huge_orders(struct inode *inode,
+				struct vm_area_struct *vma, pgoff_t index,
+				bool global_huge);
+
 struct thpsize {
 	struct kobject kobj;
 	struct list_head node;
@@ -460,6 +464,13 @@ static inline unsigned long thp_vma_allowable_orders(struct vm_area_struct *vma,
 	return 0;
 }
 
+static inline unsigned long shmem_allowable_huge_orders(struct inode *inode,
+				struct vm_area_struct *vma, pgoff_t index,
+				bool global_huge)
+{
+	return 0;
+}
+
 #define transparent_hugepage_flags 0UL
 
 #define thp_get_unmapped_area	NULL
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index c7ce28f6b7f3..ea377bb4af91 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -151,10 +151,15 @@ unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma,
 	 * Must be done before hugepage flags check since shmem has its
 	 * own flags.
 	 */
-	if (!in_pf && shmem_file(vma->vm_file))
-		return shmem_is_huge(file_inode(vma->vm_file), vma->vm_pgoff,
-				     !enforce_sysfs, vma->vm_mm, vm_flags)
-			? orders : 0;
+	if (!in_pf && shmem_file(vma->vm_file)) {
+		bool global_huge = shmem_is_huge(file_inode(vma->vm_file), vma->vm_pgoff,
+							!enforce_sysfs, vma->vm_mm, vm_flags);
+
+		if (!vma_is_anon_shmem(vma))
+			return global_huge? orders : 0;
+		return shmem_allowable_huge_orders(file_inode(vma->vm_file),
+							vma, vma->vm_pgoff, global_huge);
+	}
 
 	if (!vma_is_anonymous(vma)) {
 		/*
diff --git a/mm/shmem.c b/mm/shmem.c
index d495c0701a83..aa85df9c662a 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1622,7 +1622,7 @@ static gfp_t limit_gfp_mask(gfp_t huge_gfp, gfp_t limit_gfp)
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-static unsigned long shmem_allowable_huge_orders(struct inode *inode,
+unsigned long shmem_allowable_huge_orders(struct inode *inode,
 				struct vm_area_struct *vma, pgoff_t index,
 				bool global_huge)
 {
@@ -1707,13 +1707,6 @@ static unsigned long shmem_suitable_orders(struct inode *inode, struct vm_fault
 	return orders;
 }
 #else
-static unsigned long shmem_allowable_huge_orders(struct inode *inode,
-				struct vm_area_struct *vma, pgoff_t index,
-				bool global_huge)
-{
-	return 0;
-}
-
 static unsigned long shmem_suitable_orders(struct inode *inode, struct vm_fault *vmf,
 					   struct address_space *mapping, pgoff_t index,
 					   unsigned long orders)
-- 
2.19.1.6.gb485710b

Re: [PATCH v2] mm: thp: support "THPeligible" semantics for mTHP with anonymous shmem

[Baolin Wang]

On 2024/7/2 10:34, Bang Li wrote:
> After the commit 7fb1b252afb5 ("mm: shmem: add mTHP support for
> anonymous shmem"), we can configure different policies through
> the multi-size THP sysfs interface for anonymous shmem. But
> currently "THPeligible" indicates only whether the mapping is
> eligible for allocating THP-pages as well as the THP is PMD
> mappable or not for anonymous shmem, we need to support semantics
> for mTHP with anonymous shmem similar to those for mTHP with
> anonymous memory.
> 
> Signed-off-by: Bang Li <libang.li@antgroup.com>
> ---
> Changes since v1 [1]:
>   - Put anonymous shmem mthp related logic into
>     thp_vma_allowable_orders() (per David)
> 
> [1] https://lore.kernel.org/linux-mm/20240628104926.34209-1-libang.li@antgroup.com/
> ---
>   include/linux/huge_mm.h | 11 +++++++++++
>   mm/huge_memory.c        | 13 +++++++++----
>   mm/shmem.c              |  9 +--------
>   3 files changed, 21 insertions(+), 12 deletions(-)
> 
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index 212cca384d7e..f87136f38aa1 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -267,6 +267,10 @@ unsigned long thp_vma_allowable_orders(struct vm_area_struct *vma,
>   	return __thp_vma_allowable_orders(vma, vm_flags, tva_flags, orders);
>   }
>   
> +unsigned long shmem_allowable_huge_orders(struct inode *inode,
> +				struct vm_area_struct *vma, pgoff_t index,
> +				bool global_huge);
> +
>   struct thpsize {
>   	struct kobject kobj;
>   	struct list_head node;
> @@ -460,6 +464,13 @@ static inline unsigned long thp_vma_allowable_orders(struct vm_area_struct *vma,
>   	return 0;
>   }
>   
> +static inline unsigned long shmem_allowable_huge_orders(struct inode *inode,
> +				struct vm_area_struct *vma, pgoff_t index,
> +				bool global_huge)
> +{
> +	return 0;
> +}

This function should be placed in the ‘shmem_fs.h’ header file, just 
like shmem_is_huge().

Re: [PATCH v2] mm: thp: support "THPeligible" semantics for mTHP with anonymous shmem

[Bang Li]

Hi Baolin,

On 2024/7/2 14:14, Baolin Wang wrote:
> 
> 
> On 2024/7/2 10:34, Bang Li wrote:
>> After the commit 7fb1b252afb5 ("mm: shmem: add mTHP support for
>> anonymous shmem"), we can configure different policies through
>> the multi-size THP sysfs interface for anonymous shmem. But
>> currently "THPeligible" indicates only whether the mapping is
>> eligible for allocating THP-pages as well as the THP is PMD
>> mappable or not for anonymous shmem, we need to support semantics
>> for mTHP with anonymous shmem similar to those for mTHP with
>> anonymous memory.
>>
>> Signed-off-by: Bang Li <libang.li@antgroup.com>
>> ---
>> Changes since v1 [1]:
>>   - Put anonymous shmem mthp related logic into
>>     thp_vma_allowable_orders() (per David)
>>
>> [1] 
>> https://lore.kernel.org/linux-mm/20240628104926.34209-1-libang.li@antgroup.com/
>> ---
>>   include/linux/huge_mm.h | 11 +++++++++++
>>   mm/huge_memory.c        | 13 +++++++++----
>>   mm/shmem.c              |  9 +--------
>>   3 files changed, 21 insertions(+), 12 deletions(-)
>>
>> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
>> index 212cca384d7e..f87136f38aa1 100644
>> --- a/include/linux/huge_mm.h
>> +++ b/include/linux/huge_mm.h
>> @@ -267,6 +267,10 @@ unsigned long thp_vma_allowable_orders(struct 
>> vm_area_struct *vma,
>>       return __thp_vma_allowable_orders(vma, vm_flags, tva_flags, 
>> orders);
>>   }
>> +unsigned long shmem_allowable_huge_orders(struct inode *inode,
>> +                struct vm_area_struct *vma, pgoff_t index,
>> +                bool global_huge);
>> +
>>   struct thpsize {
>>       struct kobject kobj;
>>       struct list_head node;
>> @@ -460,6 +464,13 @@ static inline unsigned long 
>> thp_vma_allowable_orders(struct vm_area_struct *vma,
>>       return 0;
>>   }
>> +static inline unsigned long shmem_allowable_huge_orders(struct inode 
>> *inode,
>> +                struct vm_area_struct *vma, pgoff_t index,
>> +                bool global_huge)
>> +{
>> +    return 0;
>> +}
> 
> This function should be placed in the ‘shmem_fs.h’ header file, just 
> like shmem_is_huge().

Looks more reasonable，thank you for your review.

Thanks,
Bang

Re: [PATCH v2] mm: thp: support "THPeligible" semantics for mTHP with anonymous shmem

[Ryan Roberts]

On 02/07/2024 03:34, Bang Li wrote:
> After the commit 7fb1b252afb5 ("mm: shmem: add mTHP support for
> anonymous shmem"), we can configure different policies through
> the multi-size THP sysfs interface for anonymous shmem. But
> currently "THPeligible" indicates only whether the mapping is
> eligible for allocating THP-pages as well as the THP is PMD
> mappable or not for anonymous shmem, we need to support semantics
> for mTHP with anonymous shmem similar to those for mTHP with
> anonymous memory.
> 
> Signed-off-by: Bang Li <libang.li@antgroup.com>
> ---
> Changes since v1 [1]:
>  - Put anonymous shmem mthp related logic into
>    thp_vma_allowable_orders() (per David)
> 
> [1] https://lore.kernel.org/linux-mm/20240628104926.34209-1-libang.li@antgroup.com/
> ---
>  include/linux/huge_mm.h | 11 +++++++++++
>  mm/huge_memory.c        | 13 +++++++++----
>  mm/shmem.c              |  9 +--------
>  3 files changed, 21 insertions(+), 12 deletions(-)
> 
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index 212cca384d7e..f87136f38aa1 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -267,6 +267,10 @@ unsigned long thp_vma_allowable_orders(struct vm_area_struct *vma,
>  	return __thp_vma_allowable_orders(vma, vm_flags, tva_flags, orders);
>  }
>  
> +unsigned long shmem_allowable_huge_orders(struct inode *inode,
> +				struct vm_area_struct *vma, pgoff_t index,
> +				bool global_huge);
> +
>  struct thpsize {
>  	struct kobject kobj;
>  	struct list_head node;
> @@ -460,6 +464,13 @@ static inline unsigned long thp_vma_allowable_orders(struct vm_area_struct *vma,
>  	return 0;
>  }
>  
> +static inline unsigned long shmem_allowable_huge_orders(struct inode *inode,
> +				struct vm_area_struct *vma, pgoff_t index,
> +				bool global_huge)
> +{
> +	return 0;
> +}
> +
>  #define transparent_hugepage_flags 0UL
>  
>  #define thp_get_unmapped_area	NULL
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index c7ce28f6b7f3..ea377bb4af91 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -151,10 +151,15 @@ unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma,
>  	 * Must be done before hugepage flags check since shmem has its
>  	 * own flags.
>  	 */
> -	if (!in_pf && shmem_file(vma->vm_file))
> -		return shmem_is_huge(file_inode(vma->vm_file), vma->vm_pgoff,
> -				     !enforce_sysfs, vma->vm_mm, vm_flags)
> -			? orders : 0;
> +	if (!in_pf && shmem_file(vma->vm_file)) {
> +		bool global_huge = shmem_is_huge(file_inode(vma->vm_file), vma->vm_pgoff,
> +							!enforce_sysfs, vma->vm_mm, vm_flags);
> +
> +		if (!vma_is_anon_shmem(vma))
> +			return global_huge? orders : 0;

nit: missing space before '?'

> +		return shmem_allowable_huge_orders(file_inode(vma->vm_file),
> +							vma, vma->vm_pgoff, global_huge);

What's the rationale for splitting these functions into shmem_is_huge() and
shmem_allowable_huge_orders()? Why not just have a single
shmem_allowable_huge_orders() that tells you the answer?

> +	}
>  
>  	if (!vma_is_anonymous(vma)) {
>  		/*
> diff --git a/mm/shmem.c b/mm/shmem.c
> index d495c0701a83..aa85df9c662a 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -1622,7 +1622,7 @@ static gfp_t limit_gfp_mask(gfp_t huge_gfp, gfp_t limit_gfp)
>  }
>  
>  #ifdef CONFIG_TRANSPARENT_HUGEPAGE
> -static unsigned long shmem_allowable_huge_orders(struct inode *inode,
> +unsigned long shmem_allowable_huge_orders(struct inode *inode,
>  				struct vm_area_struct *vma, pgoff_t index,
>  				bool global_huge)
>  {
> @@ -1707,13 +1707,6 @@ static unsigned long shmem_suitable_orders(struct inode *inode, struct vm_fault
>  	return orders;
>  }
>  #else
> -static unsigned long shmem_allowable_huge_orders(struct inode *inode,
> -				struct vm_area_struct *vma, pgoff_t index,
> -				bool global_huge)
> -{
> -	return 0;
> -}
> -
>  static unsigned long shmem_suitable_orders(struct inode *inode, struct vm_fault *vmf,
>  					   struct address_space *mapping, pgoff_t index,
>  					   unsigned long orders)

Re: [PATCH v2] mm: thp: support "THPeligible" semantics for mTHP with anonymous shmem

[Bang Li]

Hi Ryan,

Thanks for the review!

On 2024/7/2 16:18, Ryan Roberts wrote:
> On 02/07/2024 03:34, Bang Li wrote:
>> After the commit 7fb1b252afb5 ("mm: shmem: add mTHP support for
>> anonymous shmem"), we can configure different policies through
>> the multi-size THP sysfs interface for anonymous shmem. But
>> currently "THPeligible" indicates only whether the mapping is
>> eligible for allocating THP-pages as well as the THP is PMD
>> mappable or not for anonymous shmem, we need to support semantics
>> for mTHP with anonymous shmem similar to those for mTHP with
>> anonymous memory.
>>
>> Signed-off-by: Bang Li <libang.li@antgroup.com>
>> ---
>> Changes since v1 [1]:
>>   - Put anonymous shmem mthp related logic into
>>     thp_vma_allowable_orders() (per David)
>>
>> [1] https://lore.kernel.org/linux-mm/20240628104926.34209-1-libang.li@antgroup.com/
>> ---
>>   include/linux/huge_mm.h | 11 +++++++++++
>>   mm/huge_memory.c        | 13 +++++++++----
>>   mm/shmem.c              |  9 +--------
>>   3 files changed, 21 insertions(+), 12 deletions(-)
>>
>> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
>> index 212cca384d7e..f87136f38aa1 100644
>> --- a/include/linux/huge_mm.h
>> +++ b/include/linux/huge_mm.h
>> @@ -267,6 +267,10 @@ unsigned long thp_vma_allowable_orders(struct vm_area_struct *vma,
>>   	return __thp_vma_allowable_orders(vma, vm_flags, tva_flags, orders);
>>   }
>>   
>> +unsigned long shmem_allowable_huge_orders(struct inode *inode,
>> +				struct vm_area_struct *vma, pgoff_t index,
>> +				bool global_huge);
>> +
>>   struct thpsize {
>>   	struct kobject kobj;
>>   	struct list_head node;
>> @@ -460,6 +464,13 @@ static inline unsigned long thp_vma_allowable_orders(struct vm_area_struct *vma,
>>   	return 0;
>>   }
>>   
>> +static inline unsigned long shmem_allowable_huge_orders(struct inode *inode,
>> +				struct vm_area_struct *vma, pgoff_t index,
>> +				bool global_huge)
>> +{
>> +	return 0;
>> +}
>> +
>>   #define transparent_hugepage_flags 0UL
>>   
>>   #define thp_get_unmapped_area	NULL
>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
>> index c7ce28f6b7f3..ea377bb4af91 100644
>> --- a/mm/huge_memory.c
>> +++ b/mm/huge_memory.c
>> @@ -151,10 +151,15 @@ unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma,
>>   	 * Must be done before hugepage flags check since shmem has its
>>   	 * own flags.
>>   	 */
>> -	if (!in_pf && shmem_file(vma->vm_file))
>> -		return shmem_is_huge(file_inode(vma->vm_file), vma->vm_pgoff,
>> -				     !enforce_sysfs, vma->vm_mm, vm_flags)
>> -			? orders : 0;
>> +	if (!in_pf && shmem_file(vma->vm_file)) {
>> +		bool global_huge = shmem_is_huge(file_inode(vma->vm_file), vma->vm_pgoff,
>> +							!enforce_sysfs, vma->vm_mm, vm_flags);
>> +
>> +		if (!vma_is_anon_shmem(vma))
>> +			return global_huge? orders : 0;
> 
> nit: missing space before '?'

Yes, thanks.

> 
>> +		return shmem_allowable_huge_orders(file_inode(vma->vm_file),
>> +							vma, vma->vm_pgoff, global_huge);
> 
> What's the rationale for splitting these functions into shmem_is_huge() and
> shmem_allowable_huge_orders()? Why not just have a single
> shmem_allowable_huge_orders() that tells you the answer?
> 

Currently, shmem_is_huge() is used for all shmem implementations to 
determine whether the conditions for using THP are met. And 
shmem_allowable_huge_orders() is currently mainly used for anonymous 
shmem's mTHP to obtain all orders that meet the conditions. In my 
opinion, there is no problem in separating these two functions. In the 
future, when mTHP of other shmem types is also implemented, will 
shmem_is_huge() be unnecessary?

Thanks,
Bang

>> +	}
>>   
>>   	if (!vma_is_anonymous(vma)) {
>>   		/*
>> diff --git a/mm/shmem.c b/mm/shmem.c
>> index d495c0701a83..aa85df9c662a 100644
>> --- a/mm/shmem.c
>> +++ b/mm/shmem.c
>> @@ -1622,7 +1622,7 @@ static gfp_t limit_gfp_mask(gfp_t huge_gfp, gfp_t limit_gfp)
>>   }
>>   
>>   #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>> -static unsigned long shmem_allowable_huge_orders(struct inode *inode,
>> +unsigned long shmem_allowable_huge_orders(struct inode *inode,
>>   				struct vm_area_struct *vma, pgoff_t index,
>>   				bool global_huge)
>>   {
>> @@ -1707,13 +1707,6 @@ static unsigned long shmem_suitable_orders(struct inode *inode, struct vm_fault
>>   	return orders;
>>   }
>>   #else
>> -static unsigned long shmem_allowable_huge_orders(struct inode *inode,
>> -				struct vm_area_struct *vma, pgoff_t index,
>> -				bool global_huge)
>> -{
>> -	return 0;
>> -}
>> -
>>   static unsigned long shmem_suitable_orders(struct inode *inode, struct vm_fault *vmf,
>>   					   struct address_space *mapping, pgoff_t index,
>>   					   unsigned long orders)

Re: [PATCH v2] mm: thp: support "THPeligible" semantics for mTHP with anonymous shmem

[Ryan Roberts]

On 03/07/2024 08:33, Bang Li wrote:
> Hi Ryan,
> 
> Thanks for the review!
> 
> On 2024/7/2 16:18, Ryan Roberts wrote:
>> On 02/07/2024 03:34, Bang Li wrote:
>>> After the commit 7fb1b252afb5 ("mm: shmem: add mTHP support for
>>> anonymous shmem"), we can configure different policies through
>>> the multi-size THP sysfs interface for anonymous shmem. But
>>> currently "THPeligible" indicates only whether the mapping is
>>> eligible for allocating THP-pages as well as the THP is PMD
>>> mappable or not for anonymous shmem, we need to support semantics
>>> for mTHP with anonymous shmem similar to those for mTHP with
>>> anonymous memory.
>>>
>>> Signed-off-by: Bang Li <libang.li@antgroup.com>
>>> ---
>>> Changes since v1 [1]:
>>>   - Put anonymous shmem mthp related logic into
>>>     thp_vma_allowable_orders() (per David)
>>>
>>> [1]
>>> https://lore.kernel.org/linux-mm/20240628104926.34209-1-libang.li@antgroup.com/
>>> ---
>>>   include/linux/huge_mm.h | 11 +++++++++++
>>>   mm/huge_memory.c        | 13 +++++++++----
>>>   mm/shmem.c              |  9 +--------
>>>   3 files changed, 21 insertions(+), 12 deletions(-)
>>>
>>> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
>>> index 212cca384d7e..f87136f38aa1 100644
>>> --- a/include/linux/huge_mm.h
>>> +++ b/include/linux/huge_mm.h
>>> @@ -267,6 +267,10 @@ unsigned long thp_vma_allowable_orders(struct
>>> vm_area_struct *vma,
>>>       return __thp_vma_allowable_orders(vma, vm_flags, tva_flags, orders);
>>>   }
>>>   +unsigned long shmem_allowable_huge_orders(struct inode *inode,
>>> +                struct vm_area_struct *vma, pgoff_t index,
>>> +                bool global_huge);
>>> +
>>>   struct thpsize {
>>>       struct kobject kobj;
>>>       struct list_head node;
>>> @@ -460,6 +464,13 @@ static inline unsigned long
>>> thp_vma_allowable_orders(struct vm_area_struct *vma,
>>>       return 0;
>>>   }
>>>   +static inline unsigned long shmem_allowable_huge_orders(struct inode *inode,
>>> +                struct vm_area_struct *vma, pgoff_t index,
>>> +                bool global_huge)
>>> +{
>>> +    return 0;
>>> +}
>>> +
>>>   #define transparent_hugepage_flags 0UL
>>>     #define thp_get_unmapped_area    NULL
>>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
>>> index c7ce28f6b7f3..ea377bb4af91 100644
>>> --- a/mm/huge_memory.c
>>> +++ b/mm/huge_memory.c
>>> @@ -151,10 +151,15 @@ unsigned long __thp_vma_allowable_orders(struct
>>> vm_area_struct *vma,
>>>        * Must be done before hugepage flags check since shmem has its
>>>        * own flags.
>>>        */
>>> -    if (!in_pf && shmem_file(vma->vm_file))
>>> -        return shmem_is_huge(file_inode(vma->vm_file), vma->vm_pgoff,
>>> -                     !enforce_sysfs, vma->vm_mm, vm_flags)
>>> -            ? orders : 0;
>>> +    if (!in_pf && shmem_file(vma->vm_file)) {
>>> +        bool global_huge = shmem_is_huge(file_inode(vma->vm_file),
>>> vma->vm_pgoff,
>>> +                            !enforce_sysfs, vma->vm_mm, vm_flags);
>>> +
>>> +        if (!vma_is_anon_shmem(vma))
>>> +            return global_huge? orders : 0;
>>
>> nit: missing space before '?'
> 
> Yes, thanks.
> 
>>
>>> +        return shmem_allowable_huge_orders(file_inode(vma->vm_file),
>>> +                            vma, vma->vm_pgoff, global_huge);
>>
>> What's the rationale for splitting these functions into shmem_is_huge() and
>> shmem_allowable_huge_orders()? Why not just have a single
>> shmem_allowable_huge_orders() that tells you the answer?
>>
> 
> Currently, shmem_is_huge() is used for all shmem implementations to determine
> whether the conditions for using THP are met. And shmem_allowable_huge_orders()
> is currently mainly used for anonymous shmem's mTHP to obtain all orders that
> meet the conditions. In my opinion, there is no problem in separating these two
> functions. In the future, when mTHP of other shmem types is also implemented,
> will shmem_is_huge() be unnecessary?

Personally, I consider shmem_is_huge() to be superfluous; If you have one
function, shmem_allowable_huge_orders(), that gives you all the information you
need. If the inode only allows PMD-size, then only return that bit in the field.
IMHO removing shmem_is_huge() would make things more readable.

Thanks,
Ryan

> 
> Thanks,
> Bang
> 
>>> +    }
>>>         if (!vma_is_anonymous(vma)) {
>>>           /*
>>> diff --git a/mm/shmem.c b/mm/shmem.c
>>> index d495c0701a83..aa85df9c662a 100644
>>> --- a/mm/shmem.c
>>> +++ b/mm/shmem.c
>>> @@ -1622,7 +1622,7 @@ static gfp_t limit_gfp_mask(gfp_t huge_gfp, gfp_t
>>> limit_gfp)
>>>   }
>>>     #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>>> -static unsigned long shmem_allowable_huge_orders(struct inode *inode,
>>> +unsigned long shmem_allowable_huge_orders(struct inode *inode,
>>>                   struct vm_area_struct *vma, pgoff_t index,
>>>                   bool global_huge)
>>>   {
>>> @@ -1707,13 +1707,6 @@ static unsigned long shmem_suitable_orders(struct
>>> inode *inode, struct vm_fault
>>>       return orders;
>>>   }
>>>   #else
>>> -static unsigned long shmem_allowable_huge_orders(struct inode *inode,
>>> -                struct vm_area_struct *vma, pgoff_t index,
>>> -                bool global_huge)
>>> -{
>>> -    return 0;
>>> -}
>>> -
>>>   static unsigned long shmem_suitable_orders(struct inode *inode, struct
>>> vm_fault *vmf,
>>>                          struct address_space *mapping, pgoff_t index,
>>>                          unsigned long orders)

Re: [PATCH v2] mm: thp: support "THPeligible" semantics for mTHP with anonymous shmem

[Bang Li]

On 2024/7/3 18:25, Ryan Roberts wrote:
> On 03/07/2024 08:33, Bang Li wrote:
>> Hi Ryan,
>>
>> Thanks for the review!
>>
>> On 2024/7/2 16:18, Ryan Roberts wrote:
>>> On 02/07/2024 03:34, Bang Li wrote:
>>>> After the commit 7fb1b252afb5 ("mm: shmem: add mTHP support for
>>>> anonymous shmem"), we can configure different policies through
>>>> the multi-size THP sysfs interface for anonymous shmem. But
>>>> currently "THPeligible" indicates only whether the mapping is
>>>> eligible for allocating THP-pages as well as the THP is PMD
>>>> mappable or not for anonymous shmem, we need to support semantics
>>>> for mTHP with anonymous shmem similar to those for mTHP with
>>>> anonymous memory.
>>>>
>>>> Signed-off-by: Bang Li <libang.li@antgroup.com>
>>>> ---
>>>> Changes since v1 [1]:
>>>>    - Put anonymous shmem mthp related logic into
>>>>      thp_vma_allowable_orders() (per David)
>>>>
>>>> [1]
>>>> https://lore.kernel.org/linux-mm/20240628104926.34209-1-libang.li@antgroup.com/
>>>> ---
>>>>    include/linux/huge_mm.h | 11 +++++++++++
>>>>    mm/huge_memory.c        | 13 +++++++++----
>>>>    mm/shmem.c              |  9 +--------
>>>>    3 files changed, 21 insertions(+), 12 deletions(-)
>>>>
>>>> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
>>>> index 212cca384d7e..f87136f38aa1 100644
>>>> --- a/include/linux/huge_mm.h
>>>> +++ b/include/linux/huge_mm.h
>>>> @@ -267,6 +267,10 @@ unsigned long thp_vma_allowable_orders(struct
>>>> vm_area_struct *vma,
>>>>        return __thp_vma_allowable_orders(vma, vm_flags, tva_flags, orders);
>>>>    }
>>>>    +unsigned long shmem_allowable_huge_orders(struct inode *inode,
>>>> +                struct vm_area_struct *vma, pgoff_t index,
>>>> +                bool global_huge);
>>>> +
>>>>    struct thpsize {
>>>>        struct kobject kobj;
>>>>        struct list_head node;
>>>> @@ -460,6 +464,13 @@ static inline unsigned long
>>>> thp_vma_allowable_orders(struct vm_area_struct *vma,
>>>>        return 0;
>>>>    }
>>>>    +static inline unsigned long shmem_allowable_huge_orders(struct inode *inode,
>>>> +                struct vm_area_struct *vma, pgoff_t index,
>>>> +                bool global_huge)
>>>> +{
>>>> +    return 0;
>>>> +}
>>>> +
>>>>    #define transparent_hugepage_flags 0UL
>>>>      #define thp_get_unmapped_area    NULL
>>>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
>>>> index c7ce28f6b7f3..ea377bb4af91 100644
>>>> --- a/mm/huge_memory.c
>>>> +++ b/mm/huge_memory.c
>>>> @@ -151,10 +151,15 @@ unsigned long __thp_vma_allowable_orders(struct
>>>> vm_area_struct *vma,
>>>>         * Must be done before hugepage flags check since shmem has its
>>>>         * own flags.
>>>>         */
>>>> -    if (!in_pf && shmem_file(vma->vm_file))
>>>> -        return shmem_is_huge(file_inode(vma->vm_file), vma->vm_pgoff,
>>>> -                     !enforce_sysfs, vma->vm_mm, vm_flags)
>>>> -            ? orders : 0;
>>>> +    if (!in_pf && shmem_file(vma->vm_file)) {
>>>> +        bool global_huge = shmem_is_huge(file_inode(vma->vm_file),
>>>> vma->vm_pgoff,
>>>> +                            !enforce_sysfs, vma->vm_mm, vm_flags);
>>>> +
>>>> +        if (!vma_is_anon_shmem(vma))
>>>> +            return global_huge? orders : 0;
>>>
>>> nit: missing space before '?'
>>
>> Yes, thanks.
>>
>>>
>>>> +        return shmem_allowable_huge_orders(file_inode(vma->vm_file),
>>>> +                            vma, vma->vm_pgoff, global_huge);
>>>
>>> What's the rationale for splitting these functions into shmem_is_huge() and
>>> shmem_allowable_huge_orders()? Why not just have a single
>>> shmem_allowable_huge_orders() that tells you the answer?
>>>
>>
>> Currently, shmem_is_huge() is used for all shmem implementations to determine
>> whether the conditions for using THP are met. And shmem_allowable_huge_orders()
>> is currently mainly used for anonymous shmem's mTHP to obtain all orders that
>> meet the conditions. In my opinion, there is no problem in separating these two
>> functions. In the future, when mTHP of other shmem types is also implemented,
>> will shmem_is_huge() be unnecessary?
> 
> Personally, I consider shmem_is_huge() to be superfluous; If you have one
> function, shmem_allowable_huge_orders(), that gives you all the information you
> need. If the inode only allows PMD-size, then only return that bit in the field.
> IMHO removing shmem_is_huge() would make things more readable.

Thank you very much for your opinion. I think there is no big problem in 
keeping the current interface status quo. In my opinion, when we 
implement mTHP for all shmems, it may be better to remove 
shmem_is_huge() and use shmem_allowable_huge_orders() uniformly. I 
believe that it won't be long before someone proposes a non-anonymous 
shared mTHP patchset. Anyway, thank you for your suggestion :).

Thanks,
Bang

> 
> Thanks,
> Ryan
> 
>>
>> Thanks,
>> Bang
>>
>>>> +    }
>>>>          if (!vma_is_anonymous(vma)) {
>>>>            /*
>>>> diff --git a/mm/shmem.c b/mm/shmem.c
>>>> index d495c0701a83..aa85df9c662a 100644
>>>> --- a/mm/shmem.c
>>>> +++ b/mm/shmem.c
>>>> @@ -1622,7 +1622,7 @@ static gfp_t limit_gfp_mask(gfp_t huge_gfp, gfp_t
>>>> limit_gfp)
>>>>    }
>>>>      #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>>>> -static unsigned long shmem_allowable_huge_orders(struct inode *inode,
>>>> +unsigned long shmem_allowable_huge_orders(struct inode *inode,
>>>>                    struct vm_area_struct *vma, pgoff_t index,
>>>>                    bool global_huge)
>>>>    {
>>>> @@ -1707,13 +1707,6 @@ static unsigned long shmem_suitable_orders(struct
>>>> inode *inode, struct vm_fault
>>>>        return orders;
>>>>    }
>>>>    #else
>>>> -static unsigned long shmem_allowable_huge_orders(struct inode *inode,
>>>> -                struct vm_area_struct *vma, pgoff_t index,
>>>> -                bool global_huge)
>>>> -{
>>>> -    return 0;
>>>> -}
>>>> -
>>>>    static unsigned long shmem_suitable_orders(struct inode *inode, struct
>>>> vm_fault *vmf,
>>>>                           struct address_space *mapping, pgoff_t index,
>>>>                           unsigned long orders)

Re: [PATCH v2] mm: thp: support "THPeligible" semantics for mTHP with anonymous shmem

[Ryan Roberts]

On 03/07/2024 17:02, Bang Li wrote:
> On 2024/7/3 18:25, Ryan Roberts wrote:
>> On 03/07/2024 08:33, Bang Li wrote:
>>> Hi Ryan,
>>>
>>> Thanks for the review!
>>>
>>> On 2024/7/2 16:18, Ryan Roberts wrote:
>>>> On 02/07/2024 03:34, Bang Li wrote:
>>>>> After the commit 7fb1b252afb5 ("mm: shmem: add mTHP support for
>>>>> anonymous shmem"), we can configure different policies through
>>>>> the multi-size THP sysfs interface for anonymous shmem. But
>>>>> currently "THPeligible" indicates only whether the mapping is
>>>>> eligible for allocating THP-pages as well as the THP is PMD
>>>>> mappable or not for anonymous shmem, we need to support semantics
>>>>> for mTHP with anonymous shmem similar to those for mTHP with
>>>>> anonymous memory.
>>>>>
>>>>> Signed-off-by: Bang Li <libang.li@antgroup.com>
>>>>> ---
>>>>> Changes since v1 [1]:
>>>>>    - Put anonymous shmem mthp related logic into
>>>>>      thp_vma_allowable_orders() (per David)
>>>>>
>>>>> [1]
>>>>> https://lore.kernel.org/linux-mm/20240628104926.34209-1-libang.li@antgroup.com/
>>>>> ---
>>>>>    include/linux/huge_mm.h | 11 +++++++++++
>>>>>    mm/huge_memory.c        | 13 +++++++++----
>>>>>    mm/shmem.c              |  9 +--------
>>>>>    3 files changed, 21 insertions(+), 12 deletions(-)
>>>>>
>>>>> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
>>>>> index 212cca384d7e..f87136f38aa1 100644
>>>>> --- a/include/linux/huge_mm.h
>>>>> +++ b/include/linux/huge_mm.h
>>>>> @@ -267,6 +267,10 @@ unsigned long thp_vma_allowable_orders(struct
>>>>> vm_area_struct *vma,
>>>>>        return __thp_vma_allowable_orders(vma, vm_flags, tva_flags, orders);
>>>>>    }
>>>>>    +unsigned long shmem_allowable_huge_orders(struct inode *inode,
>>>>> +                struct vm_area_struct *vma, pgoff_t index,
>>>>> +                bool global_huge);
>>>>> +
>>>>>    struct thpsize {
>>>>>        struct kobject kobj;
>>>>>        struct list_head node;
>>>>> @@ -460,6 +464,13 @@ static inline unsigned long
>>>>> thp_vma_allowable_orders(struct vm_area_struct *vma,
>>>>>        return 0;
>>>>>    }
>>>>>    +static inline unsigned long shmem_allowable_huge_orders(struct inode
>>>>> *inode,
>>>>> +                struct vm_area_struct *vma, pgoff_t index,
>>>>> +                bool global_huge)
>>>>> +{
>>>>> +    return 0;
>>>>> +}
>>>>> +
>>>>>    #define transparent_hugepage_flags 0UL
>>>>>      #define thp_get_unmapped_area    NULL
>>>>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
>>>>> index c7ce28f6b7f3..ea377bb4af91 100644
>>>>> --- a/mm/huge_memory.c
>>>>> +++ b/mm/huge_memory.c
>>>>> @@ -151,10 +151,15 @@ unsigned long __thp_vma_allowable_orders(struct
>>>>> vm_area_struct *vma,
>>>>>         * Must be done before hugepage flags check since shmem has its
>>>>>         * own flags.
>>>>>         */
>>>>> -    if (!in_pf && shmem_file(vma->vm_file))
>>>>> -        return shmem_is_huge(file_inode(vma->vm_file), vma->vm_pgoff,
>>>>> -                     !enforce_sysfs, vma->vm_mm, vm_flags)
>>>>> -            ? orders : 0;
>>>>> +    if (!in_pf && shmem_file(vma->vm_file)) {
>>>>> +        bool global_huge = shmem_is_huge(file_inode(vma->vm_file),
>>>>> vma->vm_pgoff,
>>>>> +                            !enforce_sysfs, vma->vm_mm, vm_flags);
>>>>> +
>>>>> +        if (!vma_is_anon_shmem(vma))
>>>>> +            return global_huge? orders : 0;
>>>>
>>>> nit: missing space before '?'
>>>
>>> Yes, thanks.
>>>
>>>>
>>>>> +        return shmem_allowable_huge_orders(file_inode(vma->vm_file),
>>>>> +                            vma, vma->vm_pgoff, global_huge);
>>>>
>>>> What's the rationale for splitting these functions into shmem_is_huge() and
>>>> shmem_allowable_huge_orders()? Why not just have a single
>>>> shmem_allowable_huge_orders() that tells you the answer?
>>>>
>>>
>>> Currently, shmem_is_huge() is used for all shmem implementations to determine
>>> whether the conditions for using THP are met. And shmem_allowable_huge_orders()
>>> is currently mainly used for anonymous shmem's mTHP to obtain all orders that
>>> meet the conditions. In my opinion, there is no problem in separating these two
>>> functions. In the future, when mTHP of other shmem types is also implemented,
>>> will shmem_is_huge() be unnecessary?
>>
>> Personally, I consider shmem_is_huge() to be superfluous; If you have one
>> function, shmem_allowable_huge_orders(), that gives you all the information you
>> need. If the inode only allows PMD-size, then only return that bit in the field.
>> IMHO removing shmem_is_huge() would make things more readable.
> 
> Thank you very much for your opinion. I think there is no big problem in keeping
> the current interface status quo. In my opinion, when we implement mTHP for all
> shmems, it may be better to remove shmem_is_huge() and use
> shmem_allowable_huge_orders() uniformly. I believe that it won't be long before
> someone proposes a non-anonymous shared mTHP patchset. Anyway, thank you for
> your suggestion :).

See [1] for an expanded list of concerns I have about the current state of the
interface and implementation.

Thanks,
Ryan

> 
> Thanks,
> Bang
> 
>>
>> Thanks,
>> Ryan
>>
>>>
>>> Thanks,
>>> Bang
>>>
>>>>> +    }
>>>>>          if (!vma_is_anonymous(vma)) {
>>>>>            /*
>>>>> diff --git a/mm/shmem.c b/mm/shmem.c
>>>>> index d495c0701a83..aa85df9c662a 100644
>>>>> --- a/mm/shmem.c
>>>>> +++ b/mm/shmem.c
>>>>> @@ -1622,7 +1622,7 @@ static gfp_t limit_gfp_mask(gfp_t huge_gfp, gfp_t
>>>>> limit_gfp)
>>>>>    }
>>>>>      #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>>>>> -static unsigned long shmem_allowable_huge_orders(struct inode *inode,
>>>>> +unsigned long shmem_allowable_huge_orders(struct inode *inode,
>>>>>                    struct vm_area_struct *vma, pgoff_t index,
>>>>>                    bool global_huge)
>>>>>    {
>>>>> @@ -1707,13 +1707,6 @@ static unsigned long shmem_suitable_orders(struct
>>>>> inode *inode, struct vm_fault
>>>>>        return orders;
>>>>>    }
>>>>>    #else
>>>>> -static unsigned long shmem_allowable_huge_orders(struct inode *inode,
>>>>> -                struct vm_area_struct *vma, pgoff_t index,
>>>>> -                bool global_huge)
>>>>> -{
>>>>> -    return 0;
>>>>> -}
>>>>> -
>>>>>    static unsigned long shmem_suitable_orders(struct inode *inode, struct
>>>>> vm_fault *vmf,
>>>>>                           struct address_space *mapping, pgoff_t index,
>>>>>                           unsigned long orders)

Re: [PATCH v2] mm: thp: support "THPeligible" semantics for mTHP with anonymous shmem

[Bang Li]

Hi Ryan,

On 2024/7/4 17:46, Ryan Roberts wrote:
> On 03/07/2024 17:02, Bang Li wrote:
>> On 2024/7/3 18:25, Ryan Roberts wrote:
>>> On 03/07/2024 08:33, Bang Li wrote:
>>>> Hi Ryan,
>>>>
>>>> Thanks for the review!
>>>>
>>>> On 2024/7/2 16:18, Ryan Roberts wrote:
>>>>> On 02/07/2024 03:34, Bang Li wrote:
>>>>>> After the commit 7fb1b252afb5 ("mm: shmem: add mTHP support for
>>>>>> anonymous shmem"), we can configure different policies through
>>>>>> the multi-size THP sysfs interface for anonymous shmem. But
>>>>>> currently "THPeligible" indicates only whether the mapping is
>>>>>> eligible for allocating THP-pages as well as the THP is PMD
>>>>>> mappable or not for anonymous shmem, we need to support semantics
>>>>>> for mTHP with anonymous shmem similar to those for mTHP with
>>>>>> anonymous memory.
>>>>>>
>>>>>> Signed-off-by: Bang Li <libang.li@antgroup.com>
>>>>>> ---
>>>>>> Changes since v1 [1]:
>>>>>>     - Put anonymous shmem mthp related logic into
>>>>>>       thp_vma_allowable_orders() (per David)
>>>>>>
>>>>>> [1]
>>>>>> https://lore.kernel.org/linux-mm/20240628104926.34209-1-libang.li@antgroup.com/
>>>>>> ---
>>>>>>     include/linux/huge_mm.h | 11 +++++++++++
>>>>>>     mm/huge_memory.c        | 13 +++++++++----
>>>>>>     mm/shmem.c              |  9 +--------
>>>>>>     3 files changed, 21 insertions(+), 12 deletions(-)
>>>>>>
>>>>>> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
>>>>>> index 212cca384d7e..f87136f38aa1 100644
>>>>>> --- a/include/linux/huge_mm.h
>>>>>> +++ b/include/linux/huge_mm.h
>>>>>> @@ -267,6 +267,10 @@ unsigned long thp_vma_allowable_orders(struct
>>>>>> vm_area_struct *vma,
>>>>>>         return __thp_vma_allowable_orders(vma, vm_flags, tva_flags, orders);
>>>>>>     }
>>>>>>     +unsigned long shmem_allowable_huge_orders(struct inode *inode,
>>>>>> +                struct vm_area_struct *vma, pgoff_t index,
>>>>>> +                bool global_huge);
>>>>>> +
>>>>>>     struct thpsize {
>>>>>>         struct kobject kobj;
>>>>>>         struct list_head node;
>>>>>> @@ -460,6 +464,13 @@ static inline unsigned long
>>>>>> thp_vma_allowable_orders(struct vm_area_struct *vma,
>>>>>>         return 0;
>>>>>>     }
>>>>>>     +static inline unsigned long shmem_allowable_huge_orders(struct inode
>>>>>> *inode,
>>>>>> +                struct vm_area_struct *vma, pgoff_t index,
>>>>>> +                bool global_huge)
>>>>>> +{
>>>>>> +    return 0;
>>>>>> +}
>>>>>> +
>>>>>>     #define transparent_hugepage_flags 0UL
>>>>>>       #define thp_get_unmapped_area    NULL
>>>>>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
>>>>>> index c7ce28f6b7f3..ea377bb4af91 100644
>>>>>> --- a/mm/huge_memory.c
>>>>>> +++ b/mm/huge_memory.c
>>>>>> @@ -151,10 +151,15 @@ unsigned long __thp_vma_allowable_orders(struct
>>>>>> vm_area_struct *vma,
>>>>>>          * Must be done before hugepage flags check since shmem has its
>>>>>>          * own flags.
>>>>>>          */
>>>>>> -    if (!in_pf && shmem_file(vma->vm_file))
>>>>>> -        return shmem_is_huge(file_inode(vma->vm_file), vma->vm_pgoff,
>>>>>> -                     !enforce_sysfs, vma->vm_mm, vm_flags)
>>>>>> -            ? orders : 0;
>>>>>> +    if (!in_pf && shmem_file(vma->vm_file)) {
>>>>>> +        bool global_huge = shmem_is_huge(file_inode(vma->vm_file),
>>>>>> vma->vm_pgoff,
>>>>>> +                            !enforce_sysfs, vma->vm_mm, vm_flags);
>>>>>> +
>>>>>> +        if (!vma_is_anon_shmem(vma))
>>>>>> +            return global_huge? orders : 0;
>>>>>
>>>>> nit: missing space before '?'
>>>>
>>>> Yes, thanks.
>>>>
>>>>>
>>>>>> +        return shmem_allowable_huge_orders(file_inode(vma->vm_file),
>>>>>> +                            vma, vma->vm_pgoff, global_huge);
>>>>>
>>>>> What's the rationale for splitting these functions into shmem_is_huge() and
>>>>> shmem_allowable_huge_orders()? Why not just have a single
>>>>> shmem_allowable_huge_orders() that tells you the answer?
>>>>>
>>>>
>>>> Currently, shmem_is_huge() is used for all shmem implementations to determine
>>>> whether the conditions for using THP are met. And shmem_allowable_huge_orders()
>>>> is currently mainly used for anonymous shmem's mTHP to obtain all orders that
>>>> meet the conditions. In my opinion, there is no problem in separating these two
>>>> functions. In the future, when mTHP of other shmem types is also implemented,
>>>> will shmem_is_huge() be unnecessary?
>>>
>>> Personally, I consider shmem_is_huge() to be superfluous; If you have one
>>> function, shmem_allowable_huge_orders(), that gives you all the information you
>>> need. If the inode only allows PMD-size, then only return that bit in the field.
>>> IMHO removing shmem_is_huge() would make things more readable.
>>
>> Thank you very much for your opinion. I think there is no big problem in keeping
>> the current interface status quo. In my opinion, when we implement mTHP for all
>> shmems, it may be better to remove shmem_is_huge() and use
>> shmem_allowable_huge_orders() uniformly. I believe that it won't be long before
>> someone proposes a non-anonymous shared mTHP patchset. Anyway, thank you for
>> your suggestion :).
> 
> See [1] for an expanded list of concerns I have about the current state of the
> interface and implementation.

OK, could you please send me the corresponding link ;)？

Thanks，
Bang

> 
> Thanks,
> Ryan
> 
>>
>> Thanks,
>> Bang
>>
>>>
>>> Thanks,
>>> Ryan
>>>
>>>>
>>>> Thanks,
>>>> Bang
>>>>
>>>>>> +    }
>>>>>>           if (!vma_is_anonymous(vma)) {
>>>>>>             /*
>>>>>> diff --git a/mm/shmem.c b/mm/shmem.c
>>>>>> index d495c0701a83..aa85df9c662a 100644
>>>>>> --- a/mm/shmem.c
>>>>>> +++ b/mm/shmem.c
>>>>>> @@ -1622,7 +1622,7 @@ static gfp_t limit_gfp_mask(gfp_t huge_gfp, gfp_t
>>>>>> limit_gfp)
>>>>>>     }
>>>>>>       #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>>>>>> -static unsigned long shmem_allowable_huge_orders(struct inode *inode,
>>>>>> +unsigned long shmem_allowable_huge_orders(struct inode *inode,
>>>>>>                     struct vm_area_struct *vma, pgoff_t index,
>>>>>>                     bool global_huge)
>>>>>>     {
>>>>>> @@ -1707,13 +1707,6 @@ static unsigned long shmem_suitable_orders(struct
>>>>>> inode *inode, struct vm_fault
>>>>>>         return orders;
>>>>>>     }
>>>>>>     #else
>>>>>> -static unsigned long shmem_allowable_huge_orders(struct inode *inode,
>>>>>> -                struct vm_area_struct *vma, pgoff_t index,
>>>>>> -                bool global_huge)
>>>>>> -{
>>>>>> -    return 0;
>>>>>> -}
>>>>>> -
>>>>>>     static unsigned long shmem_suitable_orders(struct inode *inode, struct
>>>>>> vm_fault *vmf,
>>>>>>                            struct address_space *mapping, pgoff_t index,
>>>>>>                            unsigned long orders)

Re: [PATCH v2] mm: thp: support "THPeligible" semantics for mTHP with anonymous shmem

[Ryan Roberts]

>>
>> See [1] for an expanded list of concerns I have about the current state of the
>> interface and implementation.
> 
> OK, could you please send me the corresponding link ;)？

Oops!

https://lore.kernel.org/linux-mm/65c37315-2741-481f-b433-cec35ef1af35@arm.com/

Re: [PATCH v2] mm: thp: support "THPeligible" semantics for mTHP with anonymous shmem

[Bang Li]

On 2024/7/4 18:25, Ryan Roberts wrote:
>>>
>>> See [1] for an expanded list of concerns I have about the current state of the
>>> interface and implementation.
>>
>> OK, could you please send me the corresponding link ;)？
> 
> Oops!
> 
> https://lore.kernel.org/linux-mm/65c37315-2741-481f-b433-cec35ef1af35@arm.com/

Thank you for providing the link. I will review the details of your 
concerns.

Best regards,
Bang