Re: [PATCH v3 7/8] mm/mempolicy: use a standard migration target allocation callback

[Michal Hocko]

On Tue 23-06-20 15:13:47, Joonsoo Kim wrote:
> From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
> 
> There is a well-defined migration target allocation callback.
> Use it.
> 
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>

Acked-by: Michal Hocko <mhocko@xxxxxxxx>

> ---
>  mm/internal.h  |  1 -
>  mm/mempolicy.c | 30 ++++++------------------------
>  mm/migrate.c   |  8 ++++++--
>  3 files changed, 12 insertions(+), 27 deletions(-)
> 
> diff --git a/mm/internal.h b/mm/internal.h
> index fb7f7fe..4f9f6b6 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -613,7 +613,6 @@ static inline bool is_migrate_highatomic_page(struct page *page)
>  }
>  
>  void setup_zone_pageset(struct zone *zone);
> -extern struct page *alloc_new_node_page(struct page *page, unsigned long node);
>  
>  struct migration_target_control {
>  	int nid;		/* preferred node id */
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index a3abf64..85a3f21 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -1065,28 +1065,6 @@ static int migrate_page_add(struct page *page, struct list_head *pagelist,
>  	return 0;
>  }
>  
> -/* page allocation callback for NUMA node migration */
> -struct page *alloc_new_node_page(struct page *page, unsigned long node)
> -{
> -	if (PageHuge(page)) {
> -		return alloc_huge_page_nodemask(
> -			page_hstate(compound_head(page)), node,
> -			NULL, __GFP_THISNODE, false);
> -	} else if (PageTransHuge(page)) {
> -		struct page *thp;
> -
> -		thp = alloc_pages_node(node,
> -			(GFP_TRANSHUGE | __GFP_THISNODE),
> -			HPAGE_PMD_ORDER);
> -		if (!thp)
> -			return NULL;
> -		prep_transhuge_page(thp);
> -		return thp;
> -	} else
> -		return __alloc_pages_node(node, GFP_HIGHUSER_MOVABLE |
> -						    __GFP_THISNODE, 0);
> -}
> -
>  /*
>   * Migrate pages from one node to a target node.
>   * Returns error or the number of pages not migrated.
> @@ -1097,6 +1075,10 @@ static int migrate_to_node(struct mm_struct *mm, int source, int dest,
>  	nodemask_t nmask;
>  	LIST_HEAD(pagelist);
>  	int err = 0;
> +	struct migration_target_control mtc = {
> +		.nid = dest,
> +		.gfp_mask = GFP_HIGHUSER_MOVABLE | __GFP_THISNODE,
> +	};
>  
>  	nodes_clear(nmask);
>  	node_set(source, nmask);
> @@ -1111,8 +1093,8 @@ static int migrate_to_node(struct mm_struct *mm, int source, int dest,
>  			flags | MPOL_MF_DISCONTIG_OK, &pagelist);
>  
>  	if (!list_empty(&pagelist)) {
> -		err = migrate_pages(&pagelist, alloc_new_node_page, NULL, dest,
> -					MIGRATE_SYNC, MR_SYSCALL);
> +		err = migrate_pages(&pagelist, alloc_migration_target, NULL,
> +				(unsigned long)&mtc, MIGRATE_SYNC, MR_SYSCALL);
>  		if (err)
>  			putback_movable_pages(&pagelist);
>  	}
> diff --git a/mm/migrate.c b/mm/migrate.c
> index 7c4cd74..1c943b0 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -1590,9 +1590,13 @@ static int do_move_pages_to_node(struct mm_struct *mm,
>  		struct list_head *pagelist, int node)
>  {
>  	int err;
> +	struct migration_target_control mtc = {
> +		.nid = node,
> +		.gfp_mask = GFP_HIGHUSER_MOVABLE | __GFP_THISNODE,
> +	};
>  
> -	err = migrate_pages(pagelist, alloc_new_node_page, NULL, node,
> -			MIGRATE_SYNC, MR_SYSCALL);
> +	err = migrate_pages(pagelist, alloc_migration_target, NULL,
> +			(unsigned long)&mtc, MIGRATE_SYNC, MR_SYSCALL);
>  	if (err)
>  		putback_movable_pages(pagelist);
>  	return err;
> -- 
> 2.7.4

-- 
Michal Hocko
SUSE Labs