| Message ID | 20170704183404.GA13813@embeddedgus (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
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@embeddedor.com> Reviewed-by: Juergen Gross <jgross@suse.com> Sorry for late answer, Juergen
Hi Juergen, On 07/21/2017 02:36 AM, Juergen Gross wrote: > 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@embeddedor.com> > > Reviewed-by: Juergen Gross <jgross@suse.com> > Thank you!
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@embeddedor.com> Committed to xen/tip.git for-linus-4.13b Thanks, Juergen
diff --git a/drivers/xen/xen-selfballoon.c b/drivers/xen/xen-selfballoon.c index 6662071..a67e955 100644 --- a/drivers/xen/xen-selfballoon.c +++ b/drivers/xen/xen-selfballoon.c @@ -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();
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> --- drivers/xen/xen-selfballoon.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)