From:   "Huang, Ying" <ying.huang@intel.com>
To:     Chen Wandun <chenwandun@huawei.com>
Cc:     <akpm@linux-foundation.org>, <linux-mm@kvack.org>,
        <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] mm/migrate: Continue to migrate for non-hugetlb folios
References: <20230129033910.1327277-1-chenwandun@huawei.com>
Date:   Sun, 29 Jan 2023 13:23:38 +0800
In-Reply-To: <20230129033910.1327277-1-chenwandun@huawei.com> (Chen Wandun's
        message of "Sun, 29 Jan 2023 11:39:10 +0800")
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Chen Wandun <chenwandun@huawei.com> writes:

> migrate_hugetlbs returns -ENOMEM when no enough hugetlb,
> however there may be free non-hugetlb folios available,
> so continue to migrate for non-hugetlb folios.
>
> Nowdays the only negtive return value of migrate_hugetlbs
> is -ENOMEM, keep compatible for coming negtive return value
> instead of ignore return value.
>
> Signed-off-by: Chen Wandun <chenwandun@huawei.com>

LGTM, Thanks!

Reviewed-by: "Huang, Ying" <ying.huang@intel.com>

>
> ---
> v1 --> v2: modify changelog and comment. thanks Huang Ying.
> ---
>  mm/migrate.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/mm/migrate.c b/mm/migrate.c
> index b971edbf32fc..68927aa06f9b 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -1939,7 +1939,8 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
>  
>  	rc_gather = migrate_hugetlbs(from, get_new_page, put_new_page, private,
>  				     mode, reason, &stats, &ret_folios);
> -	if (rc_gather < 0)
> +	/* There may be free non-hugetlb folios available, continue to migrate. */
> +	if (rc_gather < 0 && rc_gather != -ENOMEM)
>  		goto out;
>  again:
>  	nr_pages = 0;