diff mbox series

[v3,3/5] mm/huge_memory.c: add missing read-only THP checking in transparent_hugepage_enabled()

Message ID 20210511134857.1581273-4-linmiaohe@huawei.com (mailing list archive)
State New
Headers show
Series Cleanup and fixup for huge_memory | expand

Commit Message

Miaohe Lin May 11, 2021, 1:48 p.m. UTC
Since commit 99cb0dbd47a1 ("mm,thp: add read-only THP support for
(non-shmem) FS"), read-only THP file mapping is supported. But it
forgot to add checking for it in transparent_hugepage_enabled().
To fix it, we add checking for read-only THP file mapping and also
introduce helper transhuge_vma_enabled() to check whether thp is
enabled for specified vma to reduce duplicated code. We rename
transparent_hugepage_enabled to transparent_hugepage_active to make
the code easier to follow as suggested by David Hildenbrand.

Fixes: 99cb0dbd47a1 ("mm,thp: add read-only THP support for (non-shmem) FS")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
 fs/proc/task_mmu.c      |  2 +-
 include/linux/huge_mm.h | 27 ++++++++++++++++++++-------
 mm/huge_memory.c        | 11 ++++++++++-
 mm/khugepaged.c         |  4 +---
 mm/shmem.c              |  3 +--
 5 files changed, 33 insertions(+), 14 deletions(-)

Comments

Yang Shi May 13, 2021, 9:30 p.m. UTC | #1
On Tue, May 11, 2021 at 6:49 AM Miaohe Lin <linmiaohe@huawei.com> wrote:
>
> Since commit 99cb0dbd47a1 ("mm,thp: add read-only THP support for
> (non-shmem) FS"), read-only THP file mapping is supported. But it
> forgot to add checking for it in transparent_hugepage_enabled().
> To fix it, we add checking for read-only THP file mapping and also
> introduce helper transhuge_vma_enabled() to check whether thp is
> enabled for specified vma to reduce duplicated code. We rename
> transparent_hugepage_enabled to transparent_hugepage_active to make
> the code easier to follow as suggested by David Hildenbrand.
>
> Fixes: 99cb0dbd47a1 ("mm,thp: add read-only THP support for (non-shmem) FS")
> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>

Looks correct to me. Reviewed-by: Yang Shi <shy828301@gmail.com>

Just a nit below:

> ---
>  fs/proc/task_mmu.c      |  2 +-
>  include/linux/huge_mm.h | 27 ++++++++++++++++++++-------
>  mm/huge_memory.c        | 11 ++++++++++-
>  mm/khugepaged.c         |  4 +---
>  mm/shmem.c              |  3 +--
>  5 files changed, 33 insertions(+), 14 deletions(-)
>
> diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
> index fc9784544b24..7389df326edd 100644
> --- a/fs/proc/task_mmu.c
> +++ b/fs/proc/task_mmu.c
> @@ -832,7 +832,7 @@ static int show_smap(struct seq_file *m, void *v)
>         __show_smap(m, &mss, false);
>
>         seq_printf(m, "THPeligible:    %d\n",
> -                  transparent_hugepage_enabled(vma));
> +                  transparent_hugepage_active(vma));
>
>         if (arch_pkeys_enabled())
>                 seq_printf(m, "ProtectionKey:  %8u\n", vma_pkey(vma));
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index 0a526f211fec..a35c13d1f487 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -115,9 +115,19 @@ extern struct kobj_attribute shmem_enabled_attr;
>
>  extern unsigned long transparent_hugepage_flags;
>
> +static inline bool transhuge_vma_enabled(struct vm_area_struct *vma,

I'd like to have this function defined next to transhuge_vma_suitable().

> +                                         unsigned long vm_flags)
> +{
> +       /* Explicitly disabled through madvise. */
> +       if ((vm_flags & VM_NOHUGEPAGE) ||
> +           test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
> +               return false;
> +       return true;
> +}
> +
>  /*
>   * to be used on vmas which are known to support THP.
> - * Use transparent_hugepage_enabled otherwise
> + * Use transparent_hugepage_active otherwise
>   */
>  static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
>  {
> @@ -128,15 +138,12 @@ static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
>         if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_NEVER_DAX))
>                 return false;
>
> -       if (vma->vm_flags & VM_NOHUGEPAGE)
> +       if (!transhuge_vma_enabled(vma, vma->vm_flags))
>                 return false;
>
>         if (vma_is_temporary_stack(vma))
>                 return false;
>
> -       if (test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
> -               return false;
> -
>         if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_FLAG))
>                 return true;
>
> @@ -150,7 +157,7 @@ static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
>         return false;
>  }
>
> -bool transparent_hugepage_enabled(struct vm_area_struct *vma);
> +bool transparent_hugepage_active(struct vm_area_struct *vma);
>
>  static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
>                 unsigned long haddr)
> @@ -351,7 +358,7 @@ static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
>         return false;
>  }
>
> -static inline bool transparent_hugepage_enabled(struct vm_area_struct *vma)
> +static inline bool transparent_hugepage_active(struct vm_area_struct *vma)
>  {
>         return false;
>  }
> @@ -362,6 +369,12 @@ static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
>         return false;
>  }
>
> +static inline bool transhuge_vma_enabled(struct vm_area_struct *vma,
> +                                         unsigned long vm_flags)
> +{
> +       return false;
> +}
> +
>  static inline void prep_transhuge_page(struct page *page) {}
>
>  static inline bool is_transparent_hugepage(struct page *page)
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 76ca1eb2a223..4f37867eed12 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -63,7 +63,14 @@ static struct shrinker deferred_split_shrinker;
>  static atomic_t huge_zero_refcount;
>  struct page *huge_zero_page __read_mostly;
>
> -bool transparent_hugepage_enabled(struct vm_area_struct *vma)
> +static inline bool file_thp_enabled(struct vm_area_struct *vma)
> +{
> +       return transhuge_vma_enabled(vma, vma->vm_flags) && vma->vm_file &&
> +              !inode_is_open_for_write(vma->vm_file->f_inode) &&
> +              (vma->vm_flags & VM_EXEC);
> +}
> +
> +bool transparent_hugepage_active(struct vm_area_struct *vma)
>  {
>         /* The addr is used to check if the vma size fits */
>         unsigned long addr = (vma->vm_end & HPAGE_PMD_MASK) - HPAGE_PMD_SIZE;
> @@ -74,6 +81,8 @@ bool transparent_hugepage_enabled(struct vm_area_struct *vma)
>                 return __transparent_hugepage_enabled(vma);
>         if (vma_is_shmem(vma))
>                 return shmem_huge_enabled(vma);
> +       if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS))
> +               return file_thp_enabled(vma);
>
>         return false;
>  }
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index 6c0185fdd815..d97b20fad6e8 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -442,9 +442,7 @@ static inline int khugepaged_test_exit(struct mm_struct *mm)
>  static bool hugepage_vma_check(struct vm_area_struct *vma,
>                                unsigned long vm_flags)
>  {
> -       /* Explicitly disabled through madvise. */
> -       if ((vm_flags & VM_NOHUGEPAGE) ||
> -           test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
> +       if (!transhuge_vma_enabled(vma, vm_flags))
>                 return false;
>
>         /* Enabled via shmem mount options or sysfs settings. */
> diff --git a/mm/shmem.c b/mm/shmem.c
> index a08cedefbfaa..1dcbec313c70 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -4032,8 +4032,7 @@ bool shmem_huge_enabled(struct vm_area_struct *vma)
>         loff_t i_size;
>         pgoff_t off;
>
> -       if ((vma->vm_flags & VM_NOHUGEPAGE) ||
> -           test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
> +       if (!transhuge_vma_enabled(vma, vma->vm_flags))
>                 return false;
>         if (shmem_huge == SHMEM_HUGE_FORCE)
>                 return true;
> --
> 2.23.0
>
>
Miaohe Lin May 14, 2021, 1:53 a.m. UTC | #2
On 2021/5/14 5:30, Yang Shi wrote:
> On Tue, May 11, 2021 at 6:49 AM Miaohe Lin <linmiaohe@huawei.com> wrote:
>>
>> Since commit 99cb0dbd47a1 ("mm,thp: add read-only THP support for
>> (non-shmem) FS"), read-only THP file mapping is supported. But it
>> forgot to add checking for it in transparent_hugepage_enabled().
>> To fix it, we add checking for read-only THP file mapping and also
>> introduce helper transhuge_vma_enabled() to check whether thp is
>> enabled for specified vma to reduce duplicated code. We rename
>> transparent_hugepage_enabled to transparent_hugepage_active to make
>> the code easier to follow as suggested by David Hildenbrand.
>>
>> Fixes: 99cb0dbd47a1 ("mm,thp: add read-only THP support for (non-shmem) FS")
>> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
> 
> Looks correct to me. Reviewed-by: Yang Shi <shy828301@gmail.com>
> 

Many thanks for your Reviewed-by tag.

> Just a nit below:
> 
>> ---
>>  fs/proc/task_mmu.c      |  2 +-
>>  include/linux/huge_mm.h | 27 ++++++++++++++++++++-------
>>  mm/huge_memory.c        | 11 ++++++++++-
>>  mm/khugepaged.c         |  4 +---
>>  mm/shmem.c              |  3 +--
>>  5 files changed, 33 insertions(+), 14 deletions(-)
>>
>> diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
>> index fc9784544b24..7389df326edd 100644
>> --- a/fs/proc/task_mmu.c
>> +++ b/fs/proc/task_mmu.c
>> @@ -832,7 +832,7 @@ static int show_smap(struct seq_file *m, void *v)
>>         __show_smap(m, &mss, false);
>>
>>         seq_printf(m, "THPeligible:    %d\n",
>> -                  transparent_hugepage_enabled(vma));
>> +                  transparent_hugepage_active(vma));
>>
>>         if (arch_pkeys_enabled())
>>                 seq_printf(m, "ProtectionKey:  %8u\n", vma_pkey(vma));
>> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
>> index 0a526f211fec..a35c13d1f487 100644
>> --- a/include/linux/huge_mm.h
>> +++ b/include/linux/huge_mm.h
>> @@ -115,9 +115,19 @@ extern struct kobj_attribute shmem_enabled_attr;
>>
>>  extern unsigned long transparent_hugepage_flags;
>>
>> +static inline bool transhuge_vma_enabled(struct vm_area_struct *vma,
> 
> I'd like to have this function defined next to transhuge_vma_suitable().
> 

Sounds reasonable. Will do. Thanks!

>> +                                         unsigned long vm_flags)
>> +{
>> +       /* Explicitly disabled through madvise. */
>> +       if ((vm_flags & VM_NOHUGEPAGE) ||
>> +           test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
>> +               return false;
>> +       return true;
>> +}
>> +
>>  /*
>>   * to be used on vmas which are known to support THP.
>> - * Use transparent_hugepage_enabled otherwise
>> + * Use transparent_hugepage_active otherwise
>>   */
>>  static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
>>  {
>> @@ -128,15 +138,12 @@ static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
>>         if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_NEVER_DAX))
>>                 return false;
>>
>> -       if (vma->vm_flags & VM_NOHUGEPAGE)
>> +       if (!transhuge_vma_enabled(vma, vma->vm_flags))
>>                 return false;
>>
>>         if (vma_is_temporary_stack(vma))
>>                 return false;
>>
>> -       if (test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
>> -               return false;
>> -
>>         if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_FLAG))
>>                 return true;
>>
>> @@ -150,7 +157,7 @@ static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
>>         return false;
>>  }
>>
>> -bool transparent_hugepage_enabled(struct vm_area_struct *vma);
>> +bool transparent_hugepage_active(struct vm_area_struct *vma);
>>
>>  static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
>>                 unsigned long haddr)
>> @@ -351,7 +358,7 @@ static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
>>         return false;
>>  }
>>
>> -static inline bool transparent_hugepage_enabled(struct vm_area_struct *vma)
>> +static inline bool transparent_hugepage_active(struct vm_area_struct *vma)
>>  {
>>         return false;
>>  }
>> @@ -362,6 +369,12 @@ static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
>>         return false;
>>  }
>>
>> +static inline bool transhuge_vma_enabled(struct vm_area_struct *vma,
>> +                                         unsigned long vm_flags)
>> +{
>> +       return false;
>> +}
>> +
>>  static inline void prep_transhuge_page(struct page *page) {}
>>
>>  static inline bool is_transparent_hugepage(struct page *page)
>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
>> index 76ca1eb2a223..4f37867eed12 100644
>> --- a/mm/huge_memory.c
>> +++ b/mm/huge_memory.c
>> @@ -63,7 +63,14 @@ static struct shrinker deferred_split_shrinker;
>>  static atomic_t huge_zero_refcount;
>>  struct page *huge_zero_page __read_mostly;
>>
>> -bool transparent_hugepage_enabled(struct vm_area_struct *vma)
>> +static inline bool file_thp_enabled(struct vm_area_struct *vma)
>> +{
>> +       return transhuge_vma_enabled(vma, vma->vm_flags) && vma->vm_file &&
>> +              !inode_is_open_for_write(vma->vm_file->f_inode) &&
>> +              (vma->vm_flags & VM_EXEC);
>> +}
>> +
>> +bool transparent_hugepage_active(struct vm_area_struct *vma)
>>  {
>>         /* The addr is used to check if the vma size fits */
>>         unsigned long addr = (vma->vm_end & HPAGE_PMD_MASK) - HPAGE_PMD_SIZE;
>> @@ -74,6 +81,8 @@ bool transparent_hugepage_enabled(struct vm_area_struct *vma)
>>                 return __transparent_hugepage_enabled(vma);
>>         if (vma_is_shmem(vma))
>>                 return shmem_huge_enabled(vma);
>> +       if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS))
>> +               return file_thp_enabled(vma);
>>
>>         return false;
>>  }
>> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
>> index 6c0185fdd815..d97b20fad6e8 100644
>> --- a/mm/khugepaged.c
>> +++ b/mm/khugepaged.c
>> @@ -442,9 +442,7 @@ static inline int khugepaged_test_exit(struct mm_struct *mm)
>>  static bool hugepage_vma_check(struct vm_area_struct *vma,
>>                                unsigned long vm_flags)
>>  {
>> -       /* Explicitly disabled through madvise. */
>> -       if ((vm_flags & VM_NOHUGEPAGE) ||
>> -           test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
>> +       if (!transhuge_vma_enabled(vma, vm_flags))
>>                 return false;
>>
>>         /* Enabled via shmem mount options or sysfs settings. */
>> diff --git a/mm/shmem.c b/mm/shmem.c
>> index a08cedefbfaa..1dcbec313c70 100644
>> --- a/mm/shmem.c
>> +++ b/mm/shmem.c
>> @@ -4032,8 +4032,7 @@ bool shmem_huge_enabled(struct vm_area_struct *vma)
>>         loff_t i_size;
>>         pgoff_t off;
>>
>> -       if ((vma->vm_flags & VM_NOHUGEPAGE) ||
>> -           test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
>> +       if (!transhuge_vma_enabled(vma, vma->vm_flags))
>>                 return false;
>>         if (shmem_huge == SHMEM_HUGE_FORCE)
>>                 return true;
>> --
>> 2.23.0
>>
>>
> .
>
diff mbox series

Patch

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index fc9784544b24..7389df326edd 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -832,7 +832,7 @@  static int show_smap(struct seq_file *m, void *v)
 	__show_smap(m, &mss, false);
 
 	seq_printf(m, "THPeligible:    %d\n",
-		   transparent_hugepage_enabled(vma));
+		   transparent_hugepage_active(vma));
 
 	if (arch_pkeys_enabled())
 		seq_printf(m, "ProtectionKey:  %8u\n", vma_pkey(vma));
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 0a526f211fec..a35c13d1f487 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -115,9 +115,19 @@  extern struct kobj_attribute shmem_enabled_attr;
 
 extern unsigned long transparent_hugepage_flags;
 
+static inline bool transhuge_vma_enabled(struct vm_area_struct *vma,
+					  unsigned long vm_flags)
+{
+	/* Explicitly disabled through madvise. */
+	if ((vm_flags & VM_NOHUGEPAGE) ||
+	    test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
+		return false;
+	return true;
+}
+
 /*
  * to be used on vmas which are known to support THP.
- * Use transparent_hugepage_enabled otherwise
+ * Use transparent_hugepage_active otherwise
  */
 static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
 {
@@ -128,15 +138,12 @@  static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
 	if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_NEVER_DAX))
 		return false;
 
-	if (vma->vm_flags & VM_NOHUGEPAGE)
+	if (!transhuge_vma_enabled(vma, vma->vm_flags))
 		return false;
 
 	if (vma_is_temporary_stack(vma))
 		return false;
 
-	if (test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
-		return false;
-
 	if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_FLAG))
 		return true;
 
@@ -150,7 +157,7 @@  static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
 	return false;
 }
 
-bool transparent_hugepage_enabled(struct vm_area_struct *vma);
+bool transparent_hugepage_active(struct vm_area_struct *vma);
 
 static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
 		unsigned long haddr)
@@ -351,7 +358,7 @@  static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
 	return false;
 }
 
-static inline bool transparent_hugepage_enabled(struct vm_area_struct *vma)
+static inline bool transparent_hugepage_active(struct vm_area_struct *vma)
 {
 	return false;
 }
@@ -362,6 +369,12 @@  static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
 	return false;
 }
 
+static inline bool transhuge_vma_enabled(struct vm_area_struct *vma,
+					  unsigned long vm_flags)
+{
+	return false;
+}
+
 static inline void prep_transhuge_page(struct page *page) {}
 
 static inline bool is_transparent_hugepage(struct page *page)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 76ca1eb2a223..4f37867eed12 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -63,7 +63,14 @@  static struct shrinker deferred_split_shrinker;
 static atomic_t huge_zero_refcount;
 struct page *huge_zero_page __read_mostly;
 
-bool transparent_hugepage_enabled(struct vm_area_struct *vma)
+static inline bool file_thp_enabled(struct vm_area_struct *vma)
+{
+	return transhuge_vma_enabled(vma, vma->vm_flags) && vma->vm_file &&
+	       !inode_is_open_for_write(vma->vm_file->f_inode) &&
+	       (vma->vm_flags & VM_EXEC);
+}
+
+bool transparent_hugepage_active(struct vm_area_struct *vma)
 {
 	/* The addr is used to check if the vma size fits */
 	unsigned long addr = (vma->vm_end & HPAGE_PMD_MASK) - HPAGE_PMD_SIZE;
@@ -74,6 +81,8 @@  bool transparent_hugepage_enabled(struct vm_area_struct *vma)
 		return __transparent_hugepage_enabled(vma);
 	if (vma_is_shmem(vma))
 		return shmem_huge_enabled(vma);
+	if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS))
+		return file_thp_enabled(vma);
 
 	return false;
 }
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 6c0185fdd815..d97b20fad6e8 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -442,9 +442,7 @@  static inline int khugepaged_test_exit(struct mm_struct *mm)
 static bool hugepage_vma_check(struct vm_area_struct *vma,
 			       unsigned long vm_flags)
 {
-	/* Explicitly disabled through madvise. */
-	if ((vm_flags & VM_NOHUGEPAGE) ||
-	    test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
+	if (!transhuge_vma_enabled(vma, vm_flags))
 		return false;
 
 	/* Enabled via shmem mount options or sysfs settings. */
diff --git a/mm/shmem.c b/mm/shmem.c
index a08cedefbfaa..1dcbec313c70 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -4032,8 +4032,7 @@  bool shmem_huge_enabled(struct vm_area_struct *vma)
 	loff_t i_size;
 	pgoff_t off;
 
-	if ((vma->vm_flags & VM_NOHUGEPAGE) ||
-	    test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
+	if (!transhuge_vma_enabled(vma, vma->vm_flags))
 		return false;
 	if (shmem_huge == SHMEM_HUGE_FORCE)
 		return true;