Re: [PATCH v4 2/6] mm: add folio_mc_copy()

[Jane Chu <jane.chu@oracle.com>]

On 6/3/2024 2:24 AM, Kefeng Wang wrote:

> Add a #MC variant of folio_copy() which uses copy_mc_highpage() to
> support #MC handled during folio copy, it will be used in folio
> migration soon.
>
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> ---
>   include/linux/mm.h |  1 +
>   mm/util.c          | 17 +++++++++++++++++
>   2 files changed, 18 insertions(+)
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index c499d5adb748..cc21b2f0cdf8 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -1321,6 +1321,7 @@ void put_pages_list(struct list_head *pages);
>   
>   void split_page(struct page *page, unsigned int order);
>   void folio_copy(struct folio *dst, struct folio *src);
> +int folio_mc_copy(struct folio *dst, struct folio *src);
>   
>   unsigned long nr_free_buffer_pages(void);
>   
> diff --git a/mm/util.c b/mm/util.c
> index c9e519e6811f..90ea0c0f10d3 100644
> --- a/mm/util.c
> +++ b/mm/util.c
> @@ -828,6 +828,23 @@ void folio_copy(struct folio *dst, struct folio *src)
>   }
>   EXPORT_SYMBOL(folio_copy);
>   
> +int folio_mc_copy(struct folio *dst, struct folio *src)
> +{
> +	long nr = folio_nr_pages(src);
> +	long i = 0;
> +
> +	for (;;) {
> +		if (copy_mc_highpage(folio_page(dst, i), folio_page(src, i)))
> +			return -EHWPOISON;
> +		if (++i == nr)
> +			break;
> +		cond_resched();
> +	}
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(folio_mc_copy);
> +
>   int sysctl_overcommit_memory __read_mostly = OVERCOMMIT_GUESS;
>   int sysctl_overcommit_ratio __read_mostly = 50;
>   unsigned long sysctl_overcommit_kbytes __read_mostly;

Reviewed-by: Jane Chu <jane.chu@oracle.com>

thanks,

-jane