On 01/16/2020 09:41 AM, Li Xinhai wrote:
> Checking hstate at early phase when isolating page, instead of during
> unmap and move phase, to avoid useless isolation.
>
> Signed-off-by: Li Xinhai <lixinhai.lxh@xxxxxxxxx>
> Cc: Michal Hocko <mhocko@xxxxxxxx>
> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
> ---
Change log from the previous versions ?
> include/linux/hugetlb.h | 10 ++++++++++
> include/linux/mempolicy.h | 29 +----------------------------
> mm/mempolicy.c | 28 ++++++++++++++++++++++++++++
> 3 files changed, 39 insertions(+), 28 deletions(-)
>
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 31d4920..c9d871d 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -598,6 +598,11 @@ static inline bool hugepage_migration_supported(struct hstate *h)
> return arch_hugetlb_migration_supported(h);
> }
>
> +static inline bool vm_hugepage_migration_supported(struct vm_area_struct *vma)
> +{
> + return hugepage_migration_supported(hstate_vma(vma));
> +}
Another wrapper around hugepage_migration_supported() is not necessary.
> +
> /*
> * Movability check is different as compared to migration check.
> * It determines whether or not a huge page should be placed on
> @@ -809,6 +814,11 @@ static inline bool hugepage_migration_supported(struct hstate *h)
> return false;
> }
>
> +static inline bool vm_hugepage_migration_supported(struct vm_area_struct *vma)
> +{
> + return false;
> +}
> +
> static inline bool hugepage_movable_supported(struct hstate *h)
> {
> return false;
> diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
> index 5228c62..8165278 100644
> --- a/include/linux/mempolicy.h
> +++ b/include/linux/mempolicy.h
> @@ -173,34 +173,7 @@ int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
> extern void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol);
>
> /* Check if a vma is migratable */
> -static inline bool vma_migratable(struct vm_area_struct *vma)
> -{
> - if (vma->vm_flags & (VM_IO | VM_PFNMAP))
> - return false;
> -
> - /*
> - * DAX device mappings require predictable access latency, so avoid
> - * incurring periodic faults.
> - */
> - if (vma_is_dax(vma))
> - return false;
> -
> -#ifndef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
> - if (vma->vm_flags & VM_HUGETLB)
> - return false;
> -#endif
> -
> - /*
> - * Migration allocates pages in the highest zone. If we cannot
> - * do so then migration (at least from node to node) is not
> - * possible.
> - */
> - if (vma->vm_file &&
> - gfp_zone(mapping_gfp_mask(vma->vm_file->f_mapping))
> - < policy_zone)
> - return false;
> - return true;
> -}
Why vma_migratable() is being moved ?
> +extern bool vma_migratable(struct vm_area_struct *vma);
>
> extern int mpol_misplaced(struct page *, struct vm_area_struct *, unsigned long);
> extern void mpol_put_task_policy(struct task_struct *);
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index 067cf7d..8a01fb1 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -1714,6 +1714,34 @@ static int kernel_get_mempolicy(int __user *policy,
>
> #endif /* CONFIG_COMPAT */
>
> +bool vma_migratable(struct vm_area_struct *vma)
> +{
> + if (vma->vm_flags & (VM_IO | VM_PFNMAP))
> + return false;
> +
> + /*
> + * DAX device mappings require predictable access latency, so avoid
> + * incurring periodic faults.
> + */
> + if (vma_is_dax(vma))
> + return false;
> +
> + if (is_vm_hugetlb_page(vma) &&
> + !vm_hugepage_migration_supported(vma))
> + return false;
This (use hugepage_migration_supported instead) can be added above without
the code movement.
> +
> + /*
> + * Migration allocates pages in the highest zone. If we cannot
> + * do so then migration (at least from node to node) is not
> + * possible.
> + */
> + if (vma->vm_file &&
> + gfp_zone(mapping_gfp_mask(vma->vm_file->f_mapping))
> + < policy_zone)
> + return false;
> + return true;
> +}
> +
> struct mempolicy *__get_vma_policy(struct vm_area_struct *vma,
> unsigned long addr)
> {
>
