Re: [PATCH v2 4/4] mm: Generalize putback scan functions

[Daniel Jordan]

On Thu, Feb 14, 2019 at 01:35:37PM +0300, Kirill Tkhai wrote:
> +static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
> +						     struct list_head *list)
>  {
>  	struct pglist_data *pgdat = lruvec_pgdat(lruvec);
> +	int nr_pages, nr_moved = 0;
>  	LIST_HEAD(pages_to_free);
> +	struct page *page;
> +	enum lru_list lru;
>  
> -	/*
> -	 * Put back any unfreeable pages.
> -	 */
> -	while (!list_empty(page_list)) {
> -		struct page *page = lru_to_page(page_list);
> -		int lru;
> -
> +	while (!list_empty(list)) {
> +		page = lru_to_page(list);
>  		VM_BUG_ON_PAGE(PageLRU(page), page);
> -		list_del(&page->lru);
>  		if (unlikely(!page_evictable(page))) {
> +			list_del_init(&page->lru);

Why change to list_del_init?  It's more special than list_del but doesn't seem
needed since the page is list_add()ed later.

That postprocess script from patch 1 seems kinda broken before this series, and
still is.  Not that it should block this change.  Out of curiosity did you get
it to run?