Re: [PATCH] net/xdp: remove unused macro REG_STATE_NEW

[Jesper Dangaard Brouer]

On Fri,  6 Nov 2020 13:43:51 +0800
Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx> wrote:

> To tame gcc warning on it:
> net/core/xdp.c:20:0: warning: macro "REG_STATE_NEW" is not used
> [-Wunused-macros]

Hmm... REG_STATE_NEW is zero, so it is implicitly set via memset zero.
But it is true that it is technically not directly used or referenced.

It is mentioned in a comment, so please send V2 with this additional change:

$ git diff
diff --git a/net/core/xdp.c b/net/core/xdp.c
index 48aba933a5a8..6e1430971ac2 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -175,7 +175,7 @@ int xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq,
                return -ENODEV;
        }
 
-       /* State either UNREGISTERED or NEW */
+       /* State either UNREGISTERED or zero */
        xdp_rxq_info_init(xdp_rxq);
        xdp_rxq->dev = dev;
        xdp_rxq->queue_index = queue_index;


> Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> 
> Cc: Jakub Kicinski <kuba@xxxxxxxxxx> 
> Cc: Alexei Starovoitov <ast@xxxxxxxxxx> 
> Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx> 
> Cc: Jesper Dangaard Brouer <hawk@xxxxxxxxxx> 
> Cc: John Fastabend <john.fastabend@xxxxxxxxx> 
> Cc: netdev@xxxxxxxxxxxxxxx 
> Cc: bpf@xxxxxxxxxxxxxxx 
> Cc: linux-kernel@xxxxxxxxxxxxxxx 
> ---
>  net/core/xdp.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/net/core/xdp.c b/net/core/xdp.c
> index 48aba933a5a8..3d88aab19c89 100644
> --- a/net/core/xdp.c
> +++ b/net/core/xdp.c
> @@ -19,7 +19,6 @@
>  #include <trace/events/xdp.h>
>  #include <net/xdp_sock_drv.h>
>  
> -#define REG_STATE_NEW		0x0
>  #define REG_STATE_REGISTERED	0x1
>  #define REG_STATE_UNREGISTERED	0x2
>  #define REG_STATE_UNUSED	0x3



-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer