commit 024a92c1da0b5e147df01ed184fe8d655af62900
author Anthony Martin <ality@pbrane.org> Wed Nov 07 18:29:31 2012 -0800
committer Anthony Martin <ality@pbrane.org> Wed Nov 07 18:29:31 2012 -0800
tree ed8cdddf00ec472746914ed0770eba4f5eb016de
parent 122c154c605b83b3edd0324c1b038457bbc70784

runtime: use vDSO for gettimeofday on linux/amd64

Intel Core 2 Duo (2.16 GHz) running 3.6.5-1-ARCH

benchmark       old ns/op    new ns/op    delta
BenchmarkNow         1856         1034  -44.29%

R=rsc
CC=golang-dev
https://golang.org/cl/6826072

src/pkg/runtime/sys_linux_amd64.s

diff --git a/src/pkg/runtime/sys_linux_amd64.s b/src/pkg/runtime/sys_linux_amd64.s
index 88810ff..ca78ffa 100644
--- a/src/pkg/runtime/sys_linux_amd64.s
+++ b/src/pkg/runtime/sys_linux_amd64.s
@@ -104,7 +104,7 @@
 TEXT time·now(SB), 7, $32
 	LEAQ	8(SP), DI
 	MOVQ	$0, SI
-	MOVQ	$0xffffffffff600000, AX
+	MOVQ	runtime·__vdso_gettimeofday_sym(SB), AX
 	CALL	AX
 	MOVQ	8(SP), AX	// sec
 	MOVL	16(SP), DX	// usec