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Subject: Re: [PATCH] um: use swap() to make code cleaner
To:     davidcomponentone@gmail.com, jdike@addtoit.com
Cc:     richard@nod.at, johannes.berg@intel.com, yang.guang5@zte.com.cn,
        linux-um@lists.infradead.org, linux-kernel@vger.kernel.org,
        Zeal Robot <zealci@zte.com.cn>
References: <20211104061609.1496503-1-yang.guang5@zte.com.cn>
From:   Anton Ivanov <anton.ivanov@cambridgegreys.com>
Message-ID: <7f95e669-fba3-32e6-cdb9-41fb415b3b82@cambridgegreys.com>
Date:   Thu, 4 Nov 2021 14:11:22 +0000
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On 04/11/2021 06:16, davidcomponentone@gmail.com wrote:
> From: Yang Guang <yang.guang5@zte.com.cn>
> 
> Use the macro 'swap()' defined in 'include/linux/minmax.h' to avoid
> opencoding it.
> 
> Reported-by: Zeal Robot <zealci@zte.com.cn>
> Signed-off-by: Yang Guang <yang.guang5@zte.com.cn>
> ---
>   arch/um/os-Linux/sigio.c | 6 ++----
>   1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/um/os-Linux/sigio.c b/arch/um/os-Linux/sigio.c
> index 9e71794839e8..1eb15f3cfdc8 100644
> --- a/arch/um/os-Linux/sigio.c
> +++ b/arch/um/os-Linux/sigio.c
> @@ -50,7 +50,7 @@ static struct pollfds all_sigio_fds;
>   
>   static int write_sigio_thread(void *unused)
>   {
> -	struct pollfds *fds, tmp;
> +	struct pollfds *fds;
>   	struct pollfd *p;
>   	int i, n, respond_fd;
>   	char c;
> @@ -77,9 +77,7 @@ static int write_sigio_thread(void *unused)
>   					       "write_sigio_thread : "
>   					       "read on socket failed, "
>   					       "err = %d\n", errno);
> -				tmp = current_poll;
> -				current_poll = next_poll;
> -				next_poll = tmp;
> +				swap(current_poll, next_poll);
>   				respond_fd = sigio_private[1];
>   			}
>   			else {
> 

You should include minmax.h for the swap macro. While there is a very significant likelihood that it will be pulled up by another something else, it is better to do that explicitly.

-- 
Anton R. Ivanov
Cambridgegreys Limited. Registered in England. Company Number 10273661
https://www.cambridgegreys.com/