xen: selfballoon: remove unnecessary static in frontswap_selfshrink()
authorGustavo A. R. Silva <garsilva@embeddedor.com>
Tue, 4 Jul 2017 18:34:05 +0000 (13:34 -0500)
committerJuergen Gross <jgross@suse.com>
Thu, 27 Jul 2017 17:55:41 +0000 (19:55 +0200)
Remove unnecessary static on local variables last_frontswap_pages and
tgt_frontswap_pages. Such variables are initialized before being used,
on every execution path throughout the function. The statics have no
benefit and, removing them reduce 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;

You can see a significant difference in the code size after executing
the size command, before and after the code change:

before:
   text    data     bss     dec     hex filename
   5633    3452     384    9469    24fd drivers/xen/xen-selfballoon.o

after:
   text    data     bss     dec     hex filename
   5576    3308     256    9140    23b4 drivers/xen/xen-selfballoon.o

Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
drivers/xen/xen-selfballoon.c

index 66620713242a1e7416d656cca5f0353c660e1133..a67e955cacd199298a3bfa22049b5549507c52bf 100644 (file)
@@ -151,8 +151,8 @@ static unsigned long frontswap_inertia_counter;
 static void frontswap_selfshrink(void)
 {
        static unsigned long cur_frontswap_pages;
-       static unsigned long last_frontswap_pages;
-       static unsigned long tgt_frontswap_pages;
+       unsigned long last_frontswap_pages;
+       unsigned long tgt_frontswap_pages;
 
        last_frontswap_pages = cur_frontswap_pages;
        cur_frontswap_pages = frontswap_curr_pages();