[PATCH] powerpc/time: Force inlining of get_tb()

From: Christophe Leroy
Date: Sun Dec 20 2020 - 13:24:49 EST


Force inlining of get_tb() in order to avoid getting
following function in vdso32, leading to suboptimal
performance in clock_gettime()

00000688 <.get_tb>:
688: 7c 6d 42 a6 mftbu r3
68c: 7c 8c 42 a6 mftb r4
690: 7d 2d 42 a6 mftbu r9
694: 7c 03 48 40 cmplw r3,r9
698: 40 e2 ff f0 bne+ 688 <.get_tb>
69c: 4e 80 00 20 blr

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/include/asm/vdso/timebase.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/vdso/timebase.h b/arch/powerpc/include/asm/vdso/timebase.h
index b558b07959ce..881f655caa0a 100644
--- a/arch/powerpc/include/asm/vdso/timebase.h
+++ b/arch/powerpc/include/asm/vdso/timebase.h
@@ -49,7 +49,7 @@ static inline unsigned long get_tbl(void)
return mftb();
}

-static inline u64 get_tb(void)
+static __always_inline u64 get_tb(void)
{
unsigned int tbhi, tblo, tbhi2;

--
2.25.0