Message-ID: <af96ecf7-3039-784d-c276-5fc6b72611c4@linux.alibaba.com>
Date:   Thu, 16 Feb 2023 18:53:34 +0800
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Subject: Re: [PATCH v2 1/2] mm/memory_hotplug: return nothing from
 do_migrate_range()
To:     SeongJae Park <sj@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>
Cc:     David Hildenbrand <david@redhat.com>,
        Oscar Salvador <osalvador@suse.de>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
References: <20230215230300.61125-1-sj@kernel.org>
 <20230215230300.61125-2-sj@kernel.org>
From:   Baolin Wang <baolin.wang@linux.alibaba.com>
In-Reply-To: <20230215230300.61125-2-sj@kernel.org>
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On 2/16/2023 7:02 AM, SeongJae Park wrote:
> Return value mechanism of do_migrate_range() is not very simple, while
> no caller of the function checks the return value.  Make the function
> return nothing to be more simple.
> 
> Suggested-by: David Hildenbrand <david@redhat.com>
> Signed-off-by: SeongJae Park <sj@kernel.org>
> ---
>   mm/memory_hotplug.c | 5 +----
>   1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index bcb0dc41c2f2..6c615ba1a5c7 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1620,8 +1620,7 @@ static int scan_movable_pages(unsigned long start, unsigned long end,
>   	return 0;
>   }
>   
> -static int
> -do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
> +static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
>   {
>   	unsigned long pfn;
>   	struct page *page, *head;
> @@ -1721,8 +1720,6 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
>   			putback_movable_pages(&source);
>   		}
>   	}
> -
> -	return ret;

Nit: while we are at it, can we also remove the "TODO" comment in 
offline_pages()?

ret = scan_movable_pages(pfn, end_pfn, &pfn);
if (!ret) {
	/*
	 * TODO: fatal migration failures should bail
	 * out
	 */
	do_migrate_range(pfn, end_pfn);
}

With David's comments:
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>