On 05/07/2024 04:23, 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@xxxxxxxxxxxx>
LGTM!
Reviewed-by: Ryan Roberts <ryan.roberts@xxxxxxx>
> ---
> Changes since v2 [2]:
> - Move shmem_allowable_huge_orders() to shmem_fs.h (per Baolin)
> - clean up these coding style issues (per Ryan)
>
> 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@xxxxxxxxxxxx/
> [2] https://lore.kernel.org/linux-mm/20240702023401.41553-1-libang.li@xxxxxxxxxxxx/
>
> include/linux/shmem_fs.h | 9 +++++++++
> mm/huge_memory.c | 13 +++++++++----
> mm/shmem.c | 9 +--------
> 3 files changed, 19 insertions(+), 12 deletions(-)
>
> diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
> index 3fb18f7eb73e..1d06b1e5408a 100644
> --- a/include/linux/shmem_fs.h
> +++ b/include/linux/shmem_fs.h
> @@ -113,12 +113,21 @@ int shmem_unuse(unsigned int type);
> #ifdef CONFIG_TRANSPARENT_HUGEPAGE
> extern bool shmem_is_huge(struct inode *inode, pgoff_t index, bool shmem_huge_force,
> struct mm_struct *mm, unsigned long vm_flags);
> +unsigned long shmem_allowable_huge_orders(struct inode *inode,
> + struct vm_area_struct *vma, pgoff_t index,
> + bool global_huge);
> #else
> static __always_inline bool shmem_is_huge(struct inode *inode, pgoff_t index, bool shmem_huge_force,
> struct mm_struct *mm, unsigned long vm_flags)
> {
> return false;
> }
> +static inline unsigned long shmem_allowable_huge_orders(struct inode *inode,
> + struct vm_area_struct *vma, pgoff_t index,
> + bool global_huge)
> +{
> + return 0;
> +}
> #endif
>
> #ifdef CONFIG_SHMEM
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 5cbd838e96e6..0985bd75a624 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 f24177e9d5cc..921d59c3d669 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)
