[PATCH v2 4/9] x86/timer: Don't inline __const_udelay

From: Andi Kleen
Date: Fri Mar 29 2019 - 20:48:10 EST


From: Andi Kleen <ak@xxxxxxxxxxxxxxx>

LTO will happily inline __const_udelay everywhere it is used.
Forcing it noinline saves ~44k text in a LTO build.

13999560 1740864 1499136 17239560 1070e08 vmlinux-with-udelay-inline
13954764 1736768 1499136 17190668 1064f0c vmlinux-wo-udelay-inline

Even without LTO I believe marking it noinline documents it correctly.

Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
---
arch/x86/lib/delay.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/lib/delay.c b/arch/x86/lib/delay.c
index f5b7f1b3b6d7..b7375dc6898f 100644
--- a/arch/x86/lib/delay.c
+++ b/arch/x86/lib/delay.c
@@ -162,7 +162,7 @@ void __delay(unsigned long loops)
}
EXPORT_SYMBOL(__delay);

-void __const_udelay(unsigned long xloops)
+noinline void __const_udelay(unsigned long xloops)
{
unsigned long lpj = this_cpu_read(cpu_info.loops_per_jiffy) ? : loops_per_jiffy;
int d0;
--
2.20.1