Re: [PATCH 6.6 07/60] mm: migrate: convert numamigrate_isolate_page() to numamigrate_isolate_folio()

[Hugh Dickins]

On Wed, 13 Mar 2024, Sasha Levin wrote:

> From: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
> 
> [ Upstream commit 2ac9e99f3b21b2864305fbfba4bae5913274c409 ]
> 
> Rename numamigrate_isolate_page() to numamigrate_isolate_folio(), then
> make it takes a folio and use folio API to save compound_head() calls.
> 
> Link: https://lkml.kernel.org/r/20230913095131.2426871-4-wangkefeng.wang@xxxxxxxxxx
> Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
> Reviewed-by: Zi Yan <ziy@xxxxxxxxxx>
> Cc: David Hildenbrand <david@xxxxxxxxxx>
> Cc: "Huang, Ying" <ying.huang@xxxxxxxxx>
> Cc: Hugh Dickins <hughd@xxxxxxxxxx>
> Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Stable-dep-of: 2774f256e7c0 ("mm/vmscan: fix a bug calling wakeup_kswapd() with a wrong zone index")

No it is not: that one is appropriate to include, this one is not.

Hugh

> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
> ---
>  mm/migrate.c | 20 ++++++++++----------
>  1 file changed, 10 insertions(+), 10 deletions(-)
> 
> diff --git a/mm/migrate.c b/mm/migrate.c
> index c9fabb960996f..e5f2f7243a659 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -2501,10 +2501,9 @@ static struct folio *alloc_misplaced_dst_folio(struct folio *src,
>  	return __folio_alloc_node(gfp, order, nid);
>  }
>  
> -static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page)
> +static int numamigrate_isolate_folio(pg_data_t *pgdat, struct folio *folio)
>  {
> -	int nr_pages = thp_nr_pages(page);
> -	int order = compound_order(page);
> +	int nr_pages = folio_nr_pages(folio);
>  
>  	/* Avoid migrating to a node that is nearly full */
>  	if (!migrate_balanced_pgdat(pgdat, nr_pages)) {
> @@ -2516,22 +2515,23 @@ static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page)
>  			if (managed_zone(pgdat->node_zones + z))
>  				break;
>  		}
> -		wakeup_kswapd(pgdat->node_zones + z, 0, order, ZONE_MOVABLE);
> +		wakeup_kswapd(pgdat->node_zones + z, 0,
> +			      folio_order(folio), ZONE_MOVABLE);
>  		return 0;
>  	}
>  
> -	if (!isolate_lru_page(page))
> +	if (!folio_isolate_lru(folio))
>  		return 0;
>  
> -	mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON + page_is_file_lru(page),
> +	node_stat_mod_folio(folio, NR_ISOLATED_ANON + folio_is_file_lru(folio),
>  			    nr_pages);
>  
>  	/*
> -	 * Isolating the page has taken another reference, so the
> -	 * caller's reference can be safely dropped without the page
> +	 * Isolating the folio has taken another reference, so the
> +	 * caller's reference can be safely dropped without the folio
>  	 * disappearing underneath us during migration.
>  	 */
> -	put_page(page);
> +	folio_put(folio);
>  	return 1;
>  }
>  
> @@ -2565,7 +2565,7 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma,
>  	if (page_is_file_lru(page) && PageDirty(page))
>  		goto out;
>  
> -	isolated = numamigrate_isolate_page(pgdat, page);
> +	isolated = numamigrate_isolate_folio(pgdat, page_folio(page));
>  	if (!isolated)
>  		goto out;
>  
> -- 
> 2.43.0
> 
>