Re: [PATCH] mm/vmscan: Fix hard LOCKUP in function isolate_lru_folios

[Andrew Morton]

On Wed, 14 Aug 2024 17:18:25 +0800 liuye <liuye@xxxxxxxxxx> wrote:

> @@ -1669,10 +1670,12 @@ static unsigned long isolate_lru_folios(unsigned long nr_to_scan,
>  		nr_pages = folio_nr_pages(folio);
>  		total_scan += nr_pages;
>  
> -		if (folio_zonenum(folio) > sc->reclaim_idx ||
> -				skip_cma(folio, sc)) {
> +		/* Using max_nr_skipped to prevent hard LOCKUP*/
> +		if ((max_nr_skipped < SWAP_CLUSTER_MAX_SKIPPED) &&
> +			(folio_zonenum(folio) > sc->reclaim_idx || skip_cma(folio, sc))) {
>  			nr_skipped[folio_zonenum(folio)] += nr_pages;
>  			move_to = &folios_skipped;
> +			max_nr_skipped++;
>  			goto move;

This hunk is not applicable to current mainline.