diff mbox series

mm/thp: Rename TRANSPARENT_HUGEPAGE_NEVER_DAX to _UNSUPPORTED

Message ID 20230315171642.1244625-1-peterx@redhat.com
State New
Headers
Series mm/thp: Rename TRANSPARENT_HUGEPAGE_NEVER_DAX to _UNSUPPORTED |

Commit Message

Peter Xu March 15, 2023, 5:16 p.m. UTC 
  TRANSPARENT_HUGEPAGE_NEVER_DAX has nothing to do with DAX.  It's set when
has_transparent_hugepage() returns false, checked in hugepage_vma_check()
and will disable THP completely if false.  Rename it to reflect its real
purpose.

Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 include/linux/huge_mm.h | 2 +-
 mm/huge_memory.c        | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

Comments

Yang Shi March 15, 2023, 9:06 p.m. UTC | #1 
On Wed, Mar 15, 2023 at 10:16 AM Peter Xu <peterx@redhat.com> wrote:
>
> TRANSPARENT_HUGEPAGE_NEVER_DAX has nothing to do with DAX.  It's set when
> has_transparent_hugepage() returns false, checked in hugepage_vma_check()
> and will disable THP completely if false.  Rename it to reflect its real
> purpose.

Makes sense to me. Reviewed-by: Yang Shi <shy828301@gmail.com>

>
> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> Cc: Yang Shi <shy828301@gmail.com>
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
>  include/linux/huge_mm.h | 2 +-
>  mm/huge_memory.c        | 4 ++--
>  2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index 70bd867eba94..9a3a3af2dd80 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -79,7 +79,7 @@ static inline vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn,
>  }
>
>  enum transparent_hugepage_flag {
> -       TRANSPARENT_HUGEPAGE_NEVER_DAX,
> +       TRANSPARENT_HUGEPAGE_UNSUPPORTED,
>         TRANSPARENT_HUGEPAGE_FLAG,
>         TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
>         TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG,
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index b0ab247939e0..913e7dc32869 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -88,7 +88,7 @@ bool hugepage_vma_check(struct vm_area_struct *vma, unsigned long vm_flags,
>         /*
>          * If the hardware/firmware marked hugepage support disabled.
>          */
> -       if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_NEVER_DAX))
> +       if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_UNSUPPORTED))
>                 return false;
>
>         /* khugepaged doesn't collapse DAX vma, but page fault is fine. */
> @@ -464,7 +464,7 @@ static int __init hugepage_init(void)
>                  * Hardware doesn't support hugepages, hence disable
>                  * DAX PMD support.
>                  */
> -               transparent_hugepage_flags = 1 << TRANSPARENT_HUGEPAGE_NEVER_DAX;
> +               transparent_hugepage_flags = 1 << TRANSPARENT_HUGEPAGE_UNSUPPORTED;
>                 return -EINVAL;
>         }
>
> --
> 2.39.1
>
David Hildenbrand March 16, 2023, 2:57 p.m. UTC | #2 
On 15.03.23 18:16, Peter Xu wrote:
> TRANSPARENT_HUGEPAGE_NEVER_DAX has nothing to do with DAX.  It's set when
> has_transparent_hugepage() returns false, checked in hugepage_vma_check()
> and will disable THP completely if false.  Rename it to reflect its real
> purpose.
> 
> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> Cc: Yang Shi <shy828301@gmail.com>
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
>   include/linux/huge_mm.h | 2 +-
>   mm/huge_memory.c        | 4 ++--
>   2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index 70bd867eba94..9a3a3af2dd80 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -79,7 +79,7 @@ static inline vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn,
>   }
>   
>   enum transparent_hugepage_flag {
> -	TRANSPARENT_HUGEPAGE_NEVER_DAX,
> +	TRANSPARENT_HUGEPAGE_UNSUPPORTED,
>   	TRANSPARENT_HUGEPAGE_FLAG,
>   	TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
>   	TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG,
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index b0ab247939e0..913e7dc32869 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -88,7 +88,7 @@ bool hugepage_vma_check(struct vm_area_struct *vma, unsigned long vm_flags,
>   	/*
>   	 * If the hardware/firmware marked hugepage support disabled.
>   	 */
> -	if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_NEVER_DAX))
> +	if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_UNSUPPORTED))
>   		return false;
>   
>   	/* khugepaged doesn't collapse DAX vma, but page fault is fine. */
> @@ -464,7 +464,7 @@ static int __init hugepage_init(void)
>   		 * Hardware doesn't support hugepages, hence disable
>   		 * DAX PMD support.


We should also fixup that comment then, no?

Acked-by: David Hildenbrand <david@redhat.com>
Peter Xu March 16, 2023, 3:18 p.m. UTC | #3 
On Thu, Mar 16, 2023 at 03:57:12PM +0100, David Hildenbrand wrote:
> On 15.03.23 18:16, Peter Xu wrote:
> > TRANSPARENT_HUGEPAGE_NEVER_DAX has nothing to do with DAX.  It's set when
> > has_transparent_hugepage() returns false, checked in hugepage_vma_check()
> > and will disable THP completely if false.  Rename it to reflect its real
> > purpose.
> > 
> > Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> > Cc: Yang Shi <shy828301@gmail.com>
> > Signed-off-by: Peter Xu <peterx@redhat.com>
> > ---
> >   include/linux/huge_mm.h | 2 +-
> >   mm/huge_memory.c        | 4 ++--
> >   2 files changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> > index 70bd867eba94..9a3a3af2dd80 100644
> > --- a/include/linux/huge_mm.h
> > +++ b/include/linux/huge_mm.h
> > @@ -79,7 +79,7 @@ static inline vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn,
> >   }
> >   enum transparent_hugepage_flag {
> > -	TRANSPARENT_HUGEPAGE_NEVER_DAX,
> > +	TRANSPARENT_HUGEPAGE_UNSUPPORTED,
> >   	TRANSPARENT_HUGEPAGE_FLAG,
> >   	TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
> >   	TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG,
> > diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> > index b0ab247939e0..913e7dc32869 100644
> > --- a/mm/huge_memory.c
> > +++ b/mm/huge_memory.c
> > @@ -88,7 +88,7 @@ bool hugepage_vma_check(struct vm_area_struct *vma, unsigned long vm_flags,
> >   	/*
> >   	 * If the hardware/firmware marked hugepage support disabled.
> >   	 */
> > -	if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_NEVER_DAX))
> > +	if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_UNSUPPORTED))
> >   		return false;
> >   	/* khugepaged doesn't collapse DAX vma, but page fault is fine. */
> > @@ -464,7 +464,7 @@ static int __init hugepage_init(void)
> >   		 * Hardware doesn't support hugepages, hence disable
> >   		 * DAX PMD support.
> 
> 
> We should also fixup that comment then, no?

Yes, I'd drop the comment since the code explains itself.  One fixup
attached.  Thanks.
David Hildenbrand March 16, 2023, 3:37 p.m. UTC | #4 
On 16.03.23 16:18, Peter Xu wrote:
> On Thu, Mar 16, 2023 at 03:57:12PM +0100, David Hildenbrand wrote:
>> On 15.03.23 18:16, Peter Xu wrote:
>>> TRANSPARENT_HUGEPAGE_NEVER_DAX has nothing to do with DAX.  It's set when
>>> has_transparent_hugepage() returns false, checked in hugepage_vma_check()
>>> and will disable THP completely if false.  Rename it to reflect its real
>>> purpose.
>>>
>>> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
>>> Cc: Yang Shi <shy828301@gmail.com>
>>> Signed-off-by: Peter Xu <peterx@redhat.com>
>>> ---
>>>    include/linux/huge_mm.h | 2 +-
>>>    mm/huge_memory.c        | 4 ++--
>>>    2 files changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
>>> index 70bd867eba94..9a3a3af2dd80 100644
>>> --- a/include/linux/huge_mm.h
>>> +++ b/include/linux/huge_mm.h
>>> @@ -79,7 +79,7 @@ static inline vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn,
>>>    }
>>>    enum transparent_hugepage_flag {
>>> -	TRANSPARENT_HUGEPAGE_NEVER_DAX,
>>> +	TRANSPARENT_HUGEPAGE_UNSUPPORTED,
>>>    	TRANSPARENT_HUGEPAGE_FLAG,
>>>    	TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
>>>    	TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG,
>>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
>>> index b0ab247939e0..913e7dc32869 100644
>>> --- a/mm/huge_memory.c
>>> +++ b/mm/huge_memory.c
>>> @@ -88,7 +88,7 @@ bool hugepage_vma_check(struct vm_area_struct *vma, unsigned long vm_flags,
>>>    	/*
>>>    	 * If the hardware/firmware marked hugepage support disabled.
>>>    	 */
>>> -	if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_NEVER_DAX))
>>> +	if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_UNSUPPORTED))
>>>    		return false;
>>>    	/* khugepaged doesn't collapse DAX vma, but page fault is fine. */
>>> @@ -464,7 +464,7 @@ static int __init hugepage_init(void)
>>>    		 * Hardware doesn't support hugepages, hence disable
>>>    		 * DAX PMD support.
>>
>>
>> We should also fixup that comment then, no?
> 
> Yes, I'd drop the comment since the code explains itself.  One fixup
> attached.  Thanks.

LGTM
diff mbox series

Patch

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 70bd867eba94..9a3a3af2dd80 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -79,7 +79,7 @@  static inline vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn,
 }
 
 enum transparent_hugepage_flag {
-	TRANSPARENT_HUGEPAGE_NEVER_DAX,
+	TRANSPARENT_HUGEPAGE_UNSUPPORTED,
 	TRANSPARENT_HUGEPAGE_FLAG,
 	TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
 	TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG,
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index b0ab247939e0..913e7dc32869 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -88,7 +88,7 @@  bool hugepage_vma_check(struct vm_area_struct *vma, unsigned long vm_flags,
 	/*
 	 * If the hardware/firmware marked hugepage support disabled.
 	 */
-	if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_NEVER_DAX))
+	if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_UNSUPPORTED))
 		return false;
 
 	/* khugepaged doesn't collapse DAX vma, but page fault is fine. */
@@ -464,7 +464,7 @@  static int __init hugepage_init(void)
 		 * Hardware doesn't support hugepages, hence disable
 		 * DAX PMD support.
 		 */
-		transparent_hugepage_flags = 1 << TRANSPARENT_HUGEPAGE_NEVER_DAX;
+		transparent_hugepage_flags = 1 << TRANSPARENT_HUGEPAGE_UNSUPPORTED;
 		return -EINVAL;
 	}