Re: [PATCH v5 4/4] mm,hwpoison: drop unneeded pcplist draining

[Vlastimil Babka]

On 10/13/20 4:44 PM, Oscar Salvador wrote:
> memory_failure and soft_offline_path paths now drain pcplists by calling
> get_hwpoison_page.
>
> memory_failure flags the page as HWPoison before, so that page cannot
> longer go into a pcplist, and soft_offline_page only flags a page as
> HWPoison if 1) we took the page off a buddy freelist 2) the page was
> in-use and we migrated it 3) was a clean pagecache.
>
> Because of that, a page cannot longer be poisoned and be in a pcplist.
>
> Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>

Acked-by: Vlastimil Babka <vbabka@xxxxxxx>

> ---
>   mm/madvise.c | 5 -----
>   1 file changed, 5 deletions(-)
>
> diff --git a/mm/madvise.c b/mm/madvise.c
> index 416a56b8e757..c6b5524add58 100644
> --- a/mm/madvise.c
> +++ b/mm/madvise.c
> @@ -877,7 +877,6 @@ static long madvise_remove(struct vm_area_struct *vma,
>   static int madvise_inject_error(int behavior,
>   		unsigned long start, unsigned long end)
>   {
> -	struct zone *zone;
>   	unsigned long size;
>   
>   	if (!capable(CAP_SYS_ADMIN))
> @@ -922,10 +921,6 @@ static int madvise_inject_error(int behavior,
>   			return ret;
>   	}
>   
> -	/* Ensure that all poisoned pages are removed from per-cpu lists */
> -	for_each_populated_zone(zone)
> -		drain_all_pages(zone);
> -
>   	return 0;
>   }
>   #endif