[PATCH] locking/ww-mutex: use swap()

[PATCH] locking/ww-mutex: use swap()

[cgel.zte]

From: Changcheng Deng <deng.changcheng@zte.com.cn>

Use swap() in order to make code cleaner. Issue found by coccinelle.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Changcheng Deng <deng.changcheng@zte.com.cn>
---
 kernel/locking/test-ww_mutex.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/kernel/locking/test-ww_mutex.c b/kernel/locking/test-ww_mutex.c
index 353004155d65..daad819fcd16 100644
--- a/kernel/locking/test-ww_mutex.c
+++ b/kernel/locking/test-ww_mutex.c
@@ -389,7 +389,7 @@ struct stress {
 static int *get_random_order(int count)
 {
 	int *order;
-	int n, r, tmp;
+	int n, r;
 
 	order = kmalloc_array(count, sizeof(*order), GFP_KERNEL);
 	if (!order)
@@ -401,9 +401,7 @@ static int *get_random_order(int count)
 	for (n = count - 1; n > 1; n--) {
 		r = get_random_int() % (n + 1);
 		if (r != n) {
-			tmp = order[n];
-			order[n] = order[r];
-			order[r] = tmp;
+			swap(order[n], order[r]);
 		}
 	}
 
-- 
2.25.1

Re: [PATCH] locking/ww-mutex: use swap()

[Waiman Long]

On 10/18/21 11:22 PM, cgel.zte@gmail.com wrote:
> From: Changcheng Deng <deng.changcheng@zte.com.cn>
>
> Use swap() in order to make code cleaner. Issue found by coccinelle.
>
> Reported-by: Zeal Robot <zealci@zte.com.cn>
> Signed-off-by: Changcheng Deng <deng.changcheng@zte.com.cn>
> ---
>   kernel/locking/test-ww_mutex.c | 6 ++----
>   1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/locking/test-ww_mutex.c b/kernel/locking/test-ww_mutex.c
> index 353004155d65..daad819fcd16 100644
> --- a/kernel/locking/test-ww_mutex.c
> +++ b/kernel/locking/test-ww_mutex.c
> @@ -389,7 +389,7 @@ struct stress {
>   static int *get_random_order(int count)
>   {
>   	int *order;
> -	int n, r, tmp;
> +	int n, r;
>   
>   	order = kmalloc_array(count, sizeof(*order), GFP_KERNEL);
>   	if (!order)
> @@ -401,9 +401,7 @@ static int *get_random_order(int count)
>   	for (n = count - 1; n > 1; n--) {
>   		r = get_random_int() % (n + 1);
>   		if (r != n) {
> -			tmp = order[n];
> -			order[n] = order[r];
> -			order[r] = tmp;
> +			swap(order[n], order[r]);
>   		}
>   	}
>   

You can also get rid of the {} as well. I will also suggest clarifying 
in the patch title that you are cleaning up WW mutex selftest instead of 
the WW mutex code itself as that was my initial assumption when I saw 
the subject line.

Cheers,
Longman