Re: [PATCH] xen: selfballoon: remove unnecessary static in frontswap_selfshrink()

From: Juergen Gross
Date: Fri Jul 28 2017 - 05:34:43 EST


On 04/07/17 20:34, Gustavo A. R. Silva wrote:
> 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@xxxxxxxxxxxxxx>

Committed to xen/tip.git for-linus-4.13b


Thanks,

Juergen