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Date:   Mon, 09 Nov 2020 13:44:48 -0800
From:   John Fastabend <john.fastabend@gmail.com>
To:     Alex Shi <alex.shi@linux.alibaba.com>,
        Jesper Dangaard Brouer <jbrouer@redhat.com>
Cc:     davem@davemloft.net, Jakub Kicinski <kuba@kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Jesper Dangaard Brouer <hawk@kernel.org>,
        John Fastabend <john.fastabend@gmail.com>,
        netdev@vger.kernel.org, bpf@vger.kernel.org,
        linux-kernel@vger.kernel.org
Message-ID: <5fa9b850d6de5_8c0e2089d@john-XPS-13-9370.notmuch>
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Subject: Re: [PATCH] net/xdp: remove unused macro REG_STATE_NEW
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Alex Shi wrote:
> =

> =

> =E5=9C=A8 2020/11/7 =E4=B8=8A=E5=8D=8812:13, Jesper Dangaard Brouer =E5=
=86=99=E9=81=93:
> > 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:
> =

> Hi Jesper,
> =

> Thanks a lot for comments. here is the v2:
> =

> From 2908d25bf2e1c90ad71a83ba056743f45da283e8 Mon Sep 17 00:00:00 2001
> From: Alex Shi <alex.shi@linux.alibaba.com>
> Date: Fri, 6 Nov 2020 13:41:58 +0800
> Subject: [PATCH v2] net/xdp: remove unused macro REG_STATE_NEW
> =

> To tame gcc warning on it:
> net/core/xdp.c:20:0: warning: macro "REG_STATE_NEW" is not used
> [-Wunused-macros]
> And change related comments as Jesper Dangaard Brouer suggested.
> =

> Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
> ---

>  net/core/xdp.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> =

> diff --git a/net/core/xdp.c b/net/core/xdp.c
> index 48aba933a5a8..0df5ee5682d9 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

I think having the define there makes it more readable and clear what
the zero state is. But if we run with unused-macros I guess its even
uglier to try and mark it with unused attribute.

Acked-by: John Fastabend <john.fastabend@gmail.com>

> @@ -175,7 +174,7 @@ 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 =3D dev;
>  	xdp_rxq->queue_index =3D queue_index;
> -- =

> 1.8.3.1
> =