Re: [PATCH -V2 7/7] migrate_pages(): fix failure counting for retry

[Oscar Salvador]

On Mon, Jul 11, 2022 at 04:49:48PM +0800, Huang Ying wrote:
> After 10 retries, we will give up and the remaining pages will be
> counted as failure in nr_failed and nr_thp_failed.  We should count
> the failure in nr_failed_pages too.  This is done in this patch.
> 
> Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
> Fixes: 5984fabb6e82 ("mm: move_pages: report the number of non-attempted pages")
> Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
> Cc: Zi Yan <ziy@xxxxxxxxxx>
> Cc: Yang Shi <shy828301@xxxxxxxxx>

Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>

> ---
>  mm/migrate.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/mm/migrate.c b/mm/migrate.c
> index 557708ce13a1..cee6fc5a2d31 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -1345,6 +1345,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
>  	int thp_retry = 1;
>  	int nr_failed = 0;
>  	int nr_failed_pages = 0;
> +	int nr_retry_pages = 0;
>  	int nr_succeeded = 0;
>  	int nr_thp_succeeded = 0;
>  	int nr_thp_failed = 0;
> @@ -1365,6 +1366,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
>  	for (pass = 0; pass < 10 && (retry || thp_retry); pass++) {
>  		retry = 0;
>  		thp_retry = 0;
> +		nr_retry_pages = 0;
>  
>  		list_for_each_entry_safe(page, page2, from, lru) {
>  			/*
> @@ -1439,7 +1441,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
>  					nr_failed++;
>  				}
>  
> -				nr_failed_pages += nr_subpages;
> +				nr_failed_pages += nr_subpages + nr_retry_pages;
>  				/*
>  				 * There might be some subpages of fail-to-migrate THPs
>  				 * left in thp_split_pages list. Move them back to migration
> @@ -1455,6 +1457,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
>  					thp_retry++;
>  				else
>  					retry++;
> +				nr_retry_pages += nr_subpages;
>  				break;
>  			case MIGRATEPAGE_SUCCESS:
>  				nr_succeeded += nr_subpages;
> @@ -1481,6 +1484,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
>  	if (!no_subpage_counting)
>  		nr_failed += retry;
>  	nr_thp_failed += thp_retry;
> +	nr_failed_pages += nr_retry_pages;
>  	/*
>  	 * Try to migrate subpages of fail-to-migrate THPs, no nr_failed
>  	 * counting in this round, since all subpages of a THP is counted
> -- 
> 2.30.2
> 
> 

-- 
Oscar Salvador
SUSE Labs