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

Christophe Leroy christophe.leroy at csgroup.eu
Mon Dec 21 05:18:26 AEDT 2020


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 at csgroup.eu>
---
 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



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