Message-ID: <85d0ddcb-4e47-4f2e-2897-a785872b860c@redhat.com>
Date:   Thu, 16 Feb 2023 10:49:23 +0100
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Subject: Re: [PATCH v2 2/2] mm/memory_hotplug: cleanup 'ret' variable usage in
 do_migrate_range()
Content-Language: en-US
To:     SeongJae Park <sj@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>
Cc:     Oscar Salvador <osalvador@suse.de>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
References: <20230215230300.61125-1-sj@kernel.org>
 <20230215230300.61125-3-sj@kernel.org>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
In-Reply-To: <20230215230300.61125-3-sj@kernel.org>
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On 16.02.23 00:03, SeongJae Park wrote:
> Because do_migrate_range() is returning nothing, some 'ret' variable
> usages are unnecessary.  Remove unnecessary usage and reduce its scope.
> 
> Signed-off-by: SeongJae Park <sj@kernel.org>
> ---
>   mm/memory_hotplug.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 6c615ba1a5c7..6df3072d11df 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1624,7 +1624,6 @@ static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
>   {
>   	unsigned long pfn;
>   	struct page *page, *head;
> -	int ret = 0;
>   	LIST_HEAD(source);
>   	static DEFINE_RATELIMIT_STATE(migrate_rs, DEFAULT_RATELIMIT_INTERVAL,
>   				      DEFAULT_RATELIMIT_BURST);
> @@ -1678,7 +1677,6 @@ static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
>   						    page_is_file_lru(page));
>   
>   		} else {
> -			ret = -EBUSY;
>   			if (__ratelimit(&migrate_rs)) {
>   				pr_warn("failed to isolate pfn %lx\n", pfn);
>   				dump_page(page, "isolation failed");
> @@ -1692,6 +1690,7 @@ static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
>   			.nmask = &nmask,
>   			.gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL,
>   		};
> +		int ret;
>   
>   		/*
>   		 * We have checked that migration range is on a single zone so

Please squash that into the previous patch, just calling it 
"mm/memory_hotplug: cleanup return value handling in do_migrate_range()" 
or similar.

-- 
Thanks,

David / dhildenb