On 14 Jan 2021, at 14:02, Matthew Wilcox (Oracle) wrote:

> The memcg_data is only valid on the head page, not the tail pages.
> Change the format and location of the printout within the dump to
> match the other parts of struct page better.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
>  mm/debug.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/mm/debug.c b/mm/debug.c
> index 8a40b3fefbeb..0bdda8407f71 100644
> --- a/mm/debug.c
> +++ b/mm/debug.c
> @@ -110,6 +110,11 @@ void __dump_page(struct page *page, const char *reason)
>  					head_compound_mapcount(head));
>  		}
>  	}
> +
> +#ifdef CONFIG_MEMCG
> +	if (head->memcg_data)
> +		pr_warn("memcg:%lx\n", head->memcg_data);
> +#endif
>  	if (PageKsm(page))
>  		type = "ksm ";
>  	else if (PageAnon(page))
> @@ -180,11 +185,6 @@ void __dump_page(struct page *page, const char *reason)
>
>  	if (reason)
>  		pr_warn("page dumped because: %s\n", reason);
> -
> -#ifdef CONFIG_MEMCG
> -	if (!page_poisoned && page->memcg_data)
> -		pr_warn("pages's memcg:%lx\n", page->memcg_data);
> -#endif
>  }
>
>  void dump_page(struct page *page, const char *reason)
> -- 
> 2.29.2

LGTM. Reviewed-by: Zi Yan <ziy@nvidia.com>

—
Best Regards,
Yan Zi