[PATCH 08/17] net/virtio: use previous value atomic fetch operations

[Maxime Coquelin]

On 3/2/23 01:47, Tyler Retzlaff wrote:
> Use __atomic_fetch_{add,and,or,sub,xor} instead of
> __atomic_{add,and,or,sub,xor}_fetch when we have no interest in the
> result of the operation.
> 
> Reduces unnecessary codegen that provided the result of the atomic
> operation that was not used.
> 
> Change brings closer alignment with atomics available in C11 standard
> and will reduce review effort when they are integrated.
> 
> Signed-off-by: Tyler Retzlaff <roretzla at linux.microsoft.com>
> ---
>   drivers/net/virtio/virtio_user/virtio_user_dev.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
> index f46a131..2b4607a 100644
> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
> @@ -1025,7 +1025,7 @@ int virtio_user_stop_device(struct virtio_user_dev *dev)
>   		uep->id = desc_idx;
>   		uep->len = n_descs;
>   
> -		__atomic_add_fetch(&vring->used->idx, 1, __ATOMIC_RELAXED);
> +		__atomic_fetch_add(&vring->used->idx, 1, __ATOMIC_RELAXED);
>   	}
>   }
>   

Reviewed-by: Maxime Coquelin <maxime.coquelin at redhat.com>

Thanks,
Maxime