diff mbox series

net/xdp: remove unused macro REG_STATE_NEW

Message ID 1604641431-6295-1-git-send-email-alex.shi@linux.alibaba.com
State New
Headers show
Series net/xdp: remove unused macro REG_STATE_NEW | expand

Commit Message

Alex Shi Nov. 6, 2020, 5:43 a.m. UTC 
To tame gcc warning on it:
net/core/xdp.c:20:0: warning: macro "REG_STATE_NEW" is not used
[-Wunused-macros]

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

Cc: "David S. Miller" <davem@davemloft.net> 
Cc: Jakub Kicinski <kuba@kernel.org> 
Cc: Alexei Starovoitov <ast@kernel.org> 
Cc: Daniel Borkmann <daniel@iogearbox.net> 
Cc: Jesper Dangaard Brouer <hawk@kernel.org> 
Cc: John Fastabend <john.fastabend@gmail.com> 
Cc: netdev@vger.kernel.org 
Cc: bpf@vger.kernel.org 
Cc: linux-kernel@vger.kernel.org 
---
 net/core/xdp.c | 1 -
 1 file changed, 1 deletion(-)

-- 
1.8.3.1

Comments

Jesper Dangaard Brouer Nov. 6, 2020, 4:13 p.m. UTC | #1 
On Fri,  6 Nov 2020 13:43:51 +0800
Alex Shi <alex.shi@linux.alibaba.com> 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@linux.alibaba.com>

> Cc: "David S. Miller" <davem@davemloft.net> 

> Cc: Jakub Kicinski <kuba@kernel.org> 

> Cc: Alexei Starovoitov <ast@kernel.org> 

> Cc: Daniel Borkmann <daniel@iogearbox.net> 

> Cc: Jesper Dangaard Brouer <hawk@kernel.org> 

> Cc: John Fastabend <john.fastabend@gmail.com> 

> Cc: netdev@vger.kernel.org 

> Cc: bpf@vger.kernel.org 

> Cc: linux-kernel@vger.kernel.org 

> ---

>  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
Alex Shi Nov. 7, 2020, 1:08 p.m. UTC | #2 
在 2020/11/7 上午12:13, Jesper Dangaard Brouer 写道:
> 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
@@ -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 = dev;
 	xdp_rxq->queue_index = queue_index;
-- 
1.8.3.1
John Fastabend Nov. 9, 2020, 9:44 p.m. UTC | #3 
Alex Shi wrote:
> 

> 

> 在 2020/11/7 上午12:13, Jesper Dangaard Brouer 写道:

> > 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 = dev;

>  	xdp_rxq->queue_index = queue_index;

> -- 

> 1.8.3.1

>
Jesper Dangaard Brouer Nov. 10, 2020, 11:43 a.m. UTC | #4 
On Mon, 09 Nov 2020 13:44:48 -0800
John Fastabend <john.fastabend@gmail.com> wrote:

> Alex Shi wrote:

> > 

> > 

> > 在 2020/11/7 上午12:13, Jesper Dangaard Brouer 写道:  

> > > 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.


I  agree having the define there makes it more readable and clear what
the zero state is.

We can also add code that replace the comment, that check/use these
defines.  It is slow-path code, so it doesn't hurt to add this extra
code.  Generally I find it strange to "fix" these kind of warnings, but
also don't care that we do fix them if it helps someone else spot code
where it actually matters.

> 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 = dev;

> >  	xdp_rxq->queue_index = queue_index;

> > -- 

> > 1.8.3.1

> >   

> 

> 




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

Patch

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