Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1681201 > unrolled thread

[PATCH] EDAC: remove unnecessary static in edac_fake_inject_write()

Back to article view | Back to linux.kernel

Contents

  [PATCH] EDAC: remove unnecessary static in edac_fake_inject_write() "Gustavo A. R. Silva" <garsilva@embeddedor.com> - 2017-07-05 00:10 +0200
    Re: [PATCH] EDAC: remove unnecessary static in  edac_fake_inject_write() Borislav Petkov <bp@alien8.de> - 2017-07-17 10:50 +0200

#1681201 — [PATCH] EDAC: remove unnecessary static in edac_fake_inject_write()

Remove unnecessary static on local variable _type_.
Such variable is initialized before being used,
on every execution path throughout the function.
The static has no benefit and, removing it reduces
the code 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 the difference in the code size and,
also a significant difference in bss segment. This log is the output
of the size command, before and after the code change:

before:
   text    data     bss     dec     hex filename
   2966     920     128    4014     fae drivers/edac/debugfs.o

after:
   text     data     bss    dec     hex filename
   2961     832      64    3857     f11 drivers/edac/debugfs.o

Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
---
 drivers/edac/debugfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/edac/debugfs.c b/drivers/edac/debugfs.c
index 92dbb7e..ba0af49 100644
--- a/drivers/edac/debugfs.c
+++ b/drivers/edac/debugfs.c
@@ -8,7 +8,7 @@ static ssize_t edac_fake_inject_write(struct file *file,
 {
 	struct device *dev = file->private_data;
 	struct mem_ctl_info *mci = to_mci(dev);
-	static enum hw_event_mc_err_type type;
+	enum hw_event_mc_err_type type;
 	u16 errcount = mci->fake_inject_count;
 
 	if (!errcount)
-- 
2.5.0

[toc] | [next] | [standalone]

#1688767 — Re: [PATCH] EDAC: remove unnecessary static in edac_fake_inject_write()

On Tue, Jul 04, 2017 at 04:44:40PM -0500, Gustavo A. R. Silva wrote:
> Remove unnecessary static on local variable _type_.
> Such variable is initialized before being used,
> on every execution path throughout the function.
> The static has no benefit and, removing it reduces
> the code 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;

So the fix is ok but I don't understand Coccinelle to be able to judge
whether the above patch is fine or not. If it is, it probably should be
put somewhere in scripts/coccinelle/ so that others can use it too so
that they can catch such useless uses of static too.

Lemme add the Coccinelle ML to CC.

(Leaving in the rest for reference.)

> In the following log you can see the difference in the code size and,
> also a significant difference in bss segment. This log is the output
> of the size command, before and after the code change:
> 
> before:
>    text    data     bss     dec     hex filename
>    2966     920     128    4014     fae drivers/edac/debugfs.o
> 
> after:
>    text     data     bss    dec     hex filename
>    2961     832      64    3857     f11 drivers/edac/debugfs.o
> 
> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
> ---
>  drivers/edac/debugfs.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/edac/debugfs.c b/drivers/edac/debugfs.c
> index 92dbb7e..ba0af49 100644
> --- a/drivers/edac/debugfs.c
> +++ b/drivers/edac/debugfs.c
> @@ -8,7 +8,7 @@ static ssize_t edac_fake_inject_write(struct file *file,
>  {
>  	struct device *dev = file->private_data;
>  	struct mem_ctl_info *mci = to_mci(dev);
> -	static enum hw_event_mc_err_type type;
> +	enum hw_event_mc_err_type type;
>  	u16 errcount = mci->fake_inject_count;
>  
>  	if (!errcount)
> -- 
> 2.5.0
> 

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web