linux-kernel - Re: [PATCH v2 1/2] mm: use add_page_to_lru_list()/page_lru()/page_off

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Date:   Thu, 3 Sep 2020 10:28:32 +0200
From:   Michal Hocko <mhocko@...e.com>
To:     Yu Zhao <yuzhao@...gle.com>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Alex Shi <alex.shi@...ux.alibaba.com>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 1/2] mm: use
 add_page_to_lru_list()/page_lru()/page_off_lru()

On Mon 31-08-20 11:50:41, Yu Zhao wrote:
[...]
> @@ -1860,16 +1859,11 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
>  		lruvec = mem_cgroup_page_lruvec(page, pgdat);
>  
>  		SetPageLRU(page);
> -		lru = page_lru(page);
> -
> -		nr_pages = thp_nr_pages(page);
> -		update_lru_size(lruvec, lru, page_zonenum(page), nr_pages);
> -		list_move(&page->lru, &lruvec->lists[lru]);
> +		add_page_to_lru_list(page, lruvec, page_lru(page));
>  
>  		if (put_page_testzero(page)) {
>  			__ClearPageLRU(page);
> -			__ClearPageActive(page);

This should go into its own patch. The rest is a mechanical and clear.
This one needs some head scratching. E.g. Is it correct for all compound
pages. I believe it should be but few words on why would be better.

> -			del_page_from_lru_list(page, lruvec, lru);
> +			del_page_from_lru_list(page, lruvec, page_off_lru(page));
>  
>  			if (unlikely(PageCompound(page))) {
>  				spin_unlock_irq(&pgdat->lru_lock);
> @@ -1878,6 +1872,7 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
>  			} else
>  				list_add(&page->lru, &pages_to_free);
>  		} else {
> +			nr_pages = thp_nr_pages(page);
>  			nr_moved += nr_pages;
>  			if (PageActive(page))
>  				workingset_age_nonresident(lruvec, nr_pages);
> -- 
> 2.28.0.402.g5ffc5be6b7-goog
> 

-- 
Michal Hocko
SUSE Labs