Re: [PATCH] liquidio: lio_vf_main: remove unnecessary static in setup_io_queues()

[David Miller]

From: "Gustavo A. R. Silva" 
Date: Tue, 18 Jul 2017 15:50:15 -0500

> Remove unnecessary static on local variables cpu_id_modulus and cpu_id.
> Such variables are initialized before being used, on every execution
> path throughout the function. The static has no benefit and, removing
> it reduces the object file size.
> 
> This issue was detected using Coccinelle and the following semantic patch:
 ...
> Signed-off-by: Gustavo A. R. Silva 

Applied.

[PATCH] liquidio: lio_vf_main: remove unnecessary static in setup_io_queues()

[Gustavo A. R. Silva]

Remove unnecessary static on local variables cpu_id_modulus and cpu_id.
Such variables are initialized before being used, on every execution
path throughout the function. The static has no benefit and, removing
it reduces the object file size.

This issue was detected using Coccinelle and the following semantic patch:

@bad exists@
position p;
identifier x;
type T;
@@

static T x@p;
...
x = <+...x...+>

@@
identifier x;
expression e;
type T;
position p != bad.p;
@@

-static
 T x@p;
 ... when != x
 when strict
?x = e;

In the following log you can see a significant difference in the object
file size. Also, there is a significant difference in the bss segment.
This log is the output of the size command, before and after the code
change:

before:
   textdata bss dec hex filename
  55656   10680 576   66912   10560 
drivers/net/ethernet/cavium/liquidio/lio_vf_main.o

after:
   textdata bss dec hex filename
  55796   10536 448   66780   104dc 
drivers/net/ethernet/cavium/liquidio/lio_vf_main.o

Signed-off-by: Gustavo A. R. Silva 
---
 drivers/net/ethernet/cavium/liquidio/lio_vf_main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c 
b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
index 9b24710..935ff29 100644
--- a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
+++ b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
@@ -1663,10 +1663,10 @@ static int setup_io_queues(struct octeon_device 
*octeon_dev, int ifidx)
 {
struct octeon_droq_ops droq_ops;
struct net_device *netdev;
-   static int cpu_id_modulus;
+   int cpu_id_modulus;
struct octeon_droq *droq;
struct napi_struct *napi;
-   static int cpu_id;
+   int cpu_id;
int num_tx_descs;
struct lio *lio;
int retval = 0;
-- 
2.5.0

Re: [PATCH] liquidio: lio_vf_main: remove unnecessary static in setup_io_queues()

[Felix Manlunas]

On Tue, Jul 18, 2017 at 03:50:15PM -0500, Gustavo A. R. Silva wrote:
> Remove unnecessary static on local variables cpu_id_modulus and cpu_id.
> Such variables are initialized before being used, on every execution
> path throughout the function. The static has no benefit and, removing
> it reduces the object file size.
> 
> This issue was detected using Coccinelle and the following semantic patch:
> 
> @bad exists@
> position p;
> identifier x;
> type T;
> @@
> 
> static T x@p;
> ...
> x = <+...x...+>
> 
> @@
> identifier x;
> expression e;
> type T;
> position p != bad.p;
> @@
> 
> -static
>  T x@p;
>  ... when != x
>  when strict
> ?x = e;
> 
> In the following log you can see a significant difference in the object
> file size. Also, there is a significant difference in the bss segment.
> This log is the output of the size command, before and after the code
> change:
> 
> before:
>textdata bss dec hex filename
>   55656   10680 576   66912   10560 
> drivers/net/ethernet/cavium/liquidio/lio_vf_main.o
> 
> after:
>textdata bss dec hex filename
>   55796   10536 448   66780   104dc 
> drivers/net/ethernet/cavium/liquidio/lio_vf_main.o
> 
> Signed-off-by: Gustavo A. R. Silva 
> ---
>  drivers/net/ethernet/cavium/liquidio/lio_vf_main.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c 
> b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
> index 9b24710..935ff29 100644
> --- a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
> +++ b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
> @@ -1663,10 +1663,10 @@ static int setup_io_queues(struct octeon_device 
> *octeon_dev, int ifidx)
>  {
>   struct octeon_droq_ops droq_ops;
>   struct net_device *netdev;
> - static int cpu_id_modulus;
> + int cpu_id_modulus;
>   struct octeon_droq *droq;
>   struct napi_struct *napi;
> - static int cpu_id;
> + int cpu_id;
>   int num_tx_descs;
>   struct lio *lio;
>   int retval = 0;
> -- 
> 2.5.0
> 

Thanks.

Acked-by: Felix Manlunas