On Mon Apr 28, 2025 at 10:41 PM EDT, Yafang Shao wrote:
> The functions hugepage_global_{enabled,always}() are currently only used in
> mm/huge_memory.c, so we can move them to mm/internal.h. They will also be
> exposed for BPF hooking in a future change.
Why cannot BPF include huge_mm.h instead?
>
> Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
> ---
> include/linux/huge_mm.h | 54 +----------------------------------------
> mm/huge_memory.c | 46 ++++++++++++++++++++++++++++++++---
> mm/internal.h | 14 +++++++++++
> 3 files changed, 57 insertions(+), 57 deletions(-)
>
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index e893d546a49f..5e92db48fc99 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -177,19 +177,6 @@ extern unsigned long huge_anon_orders_always;
> extern unsigned long huge_anon_orders_madvise;
> extern unsigned long huge_anon_orders_inherit;
>
> -static inline bool hugepage_global_enabled(void)
> -{
> - return transparent_hugepage_flags &
> - ((1<<TRANSPARENT_HUGEPAGE_FLAG) |
> - (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG));
> -}
> -
> -static inline bool hugepage_global_always(void)
> -{
> - return transparent_hugepage_flags &
> - (1<<TRANSPARENT_HUGEPAGE_FLAG);
> -}
> -
> static inline int highest_order(unsigned long orders)
> {
> return fls_long(orders) - 1;
> @@ -260,49 +247,10 @@ static inline unsigned long thp_vma_suitable_orders(struct vm_area_struct *vma,
> return orders;
> }
>
> -unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma,
> - unsigned long vm_flags,
> - unsigned long tva_flags,
> - unsigned long orders);
> -
> -/**
> - * thp_vma_allowable_orders - determine hugepage orders that are allowed for vma
> - * @vma: the vm area to check
> - * @vm_flags: use these vm_flags instead of vma->vm_flags
> - * @tva_flags: Which TVA flags to honour
> - * @orders: bitfield of all orders to consider
> - *
> - * Calculates the intersection of the requested hugepage orders and the allowed
> - * hugepage orders for the provided vma. Permitted orders are encoded as a set
> - * bit at the corresponding bit position (bit-2 corresponds to order-2, bit-3
> - * corresponds to order-3, etc). Order-0 is never considered a hugepage order.
> - *
> - * Return: bitfield of orders allowed for hugepage in the vma. 0 if no hugepage
> - * orders are allowed.
> - */
> -static inline
> unsigned long thp_vma_allowable_orders(struct vm_area_struct *vma,
> unsigned long vm_flags,
> unsigned long tva_flags,
> - unsigned long orders)
> -{
> - /* Optimization to check if required orders are enabled early. */
> - if ((tva_flags & TVA_ENFORCE_SYSFS) && vma_is_anonymous(vma)) {
> - unsigned long mask = READ_ONCE(huge_anon_orders_always);
> -
> - if (vm_flags & VM_HUGEPAGE)
> - mask |= READ_ONCE(huge_anon_orders_madvise);
> - if (hugepage_global_always() ||
> - ((vm_flags & VM_HUGEPAGE) && hugepage_global_enabled()))
> - mask |= READ_ONCE(huge_anon_orders_inherit);
> -
> - orders &= mask;
> - if (!orders)
> - return 0;
> - }
> -
> - return __thp_vma_allowable_orders(vma, vm_flags, tva_flags, orders);
> -}
> + unsigned long orders);
>
> struct thpsize {
> struct kobject kobj;
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 2a47682d1ab7..39afa14af2f2 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -98,10 +98,10 @@ static inline bool file_thp_enabled(struct vm_area_struct *vma)
> return !inode_is_open_for_write(inode) && S_ISREG(inode->i_mode);
> }
>
> -unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma,
> - unsigned long vm_flags,
> - unsigned long tva_flags,
> - unsigned long orders)
> +static unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma,
> + unsigned long vm_flags,
> + unsigned long tva_flags,
> + unsigned long orders)
> {
> bool smaps = tva_flags & TVA_SMAPS;
> bool in_pf = tva_flags & TVA_IN_PF;
> @@ -208,6 +208,44 @@ unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma,
> return orders;
> }
>
> +/**
> + * thp_vma_allowable_orders - determine hugepage orders that are allowed for vma
> + * @vma: the vm area to check
> + * @vm_flags: use these vm_flags instead of vma->vm_flags
> + * @tva_flags: Which TVA flags to honour
> + * @orders: bitfield of all orders to consider
> + *
> + * Calculates the intersection of the requested hugepage orders and the allowed
> + * hugepage orders for the provided vma. Permitted orders are encoded as a set
> + * bit at the corresponding bit position (bit-2 corresponds to order-2, bit-3
> + * corresponds to order-3, etc). Order-0 is never considered a hugepage order.
> + *
> + * Return: bitfield of orders allowed for hugepage in the vma. 0 if no hugepage
> + * orders are allowed.
> + */
> +unsigned long thp_vma_allowable_orders(struct vm_area_struct *vma,
> + unsigned long vm_flags,
> + unsigned long tva_flags,
> + unsigned long orders)
> +{
> + /* Optimization to check if required orders are enabled early. */
> + if ((tva_flags & TVA_ENFORCE_SYSFS) && vma_is_anonymous(vma)) {
> + unsigned long mask = READ_ONCE(huge_anon_orders_always);
> +
> + if (vm_flags & VM_HUGEPAGE)
> + mask |= READ_ONCE(huge_anon_orders_madvise);
> + if (hugepage_global_always() ||
> + ((vm_flags & VM_HUGEPAGE) && hugepage_global_enabled()))
> + mask |= READ_ONCE(huge_anon_orders_inherit);
> +
> + orders &= mask;
> + if (!orders)
> + return 0;
> + }
> +
> + return __thp_vma_allowable_orders(vma, vm_flags, tva_flags, orders);
> +}
> +
> static bool get_huge_zero_page(void)
> {
> struct folio *zero_folio;
> diff --git a/mm/internal.h b/mm/internal.h
> index e9695baa5922..462d85c2ba7b 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -1625,5 +1625,19 @@ static inline bool reclaim_pt_is_enabled(unsigned long start, unsigned long end,
> }
> #endif /* CONFIG_PT_RECLAIM */
>
> +#ifdef CONFIG_TRANSPARENT_HUGEPAGE
> +static inline bool hugepage_global_enabled(void)
> +{
> + return transparent_hugepage_flags &
> + ((1<<TRANSPARENT_HUGEPAGE_FLAG) |
> + (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG));
> +}
> +
> +static inline bool hugepage_global_always(void)
> +{
> + return transparent_hugepage_flags &
> + (1<<TRANSPARENT_HUGEPAGE_FLAG);
> +}
> +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
>
> #endif /* __MM_INTERNAL_H */
--
Best Regards,
Yan, Zi
