From 7777bac6e4570ffe485f736e79f0631a460171f4 Mon Sep 17 00:00:00 2001 From: Shenghou Ma Date: Tue, 18 Dec 2012 22:57:25 +0800 Subject: runtime: use clock_gettime to get ns resolution for time.now & runtime.nanotime For Linux/{386,arm}, FreeBSD/{386,amd64,arm}, NetBSD/{386,amd64}, OpenBSD/{386,amd64}. Note: our Darwin implementation already has ns resolution. Linux/386 (Core i7-2600 @ 3.40GHz, kernel 3.5.2-gentoo) benchmark old ns/op new ns/op delta BenchmarkNow 110 118 +7.27% Linux/ARM (ARM Cortex-A8 @ 800MHz, kernel 2.6.32.28 android) benchmark old ns/op new ns/op delta BenchmarkNow 625 542 -13.28% Linux/ARM (ARM Cortex-A9 @ 1GHz, Pandaboard) benchmark old ns/op new ns/op delta BenchmarkNow 992 909 -8.37% FreeBSD 9-REL-p1/amd64 (Dell R610 Server with Xeon X5650 @ 2.67GHz) benchmark old ns/op new ns/op delta BenchmarkNow 699 695 -0.57% FreeBSD 9-REL-p1/amd64 (Atom D525 @ 1.80GHz) benchmark old ns/op new ns/op delta BenchmarkNow 1553 1658 +6.76% OpenBSD/amd64 (Dell E6410 with i5 CPU M 540 @ 2.53GHz) benchmark old ns/op new ns/op delta BenchmarkNow 1262 1236 -2.06% OpenBSD/i386 (Asus eeePC 701 with Intel Celeron M 900MHz - locked to 631MHz) benchmark old ns/op new ns/op delta BenchmarkNow 5089 5043 -0.90% NetBSD/i386 (VMware VM with Core i5 CPU @ 2.7GHz) benchmark old ns/op new ns/op delta BenchmarkNow 277 278 +0.36% NetBSD/amd64 (VMware VM with Core i5 CPU @ 2.7Ghz) benchmark old ns/op new ns/op delta BenchmarkNow 103 105 +1.94% Thanks Maxim Khitrov, Joel Sing, and Dave Cheney for providing benchmark data. R=jsing, dave, rsc CC=golang-dev https://golang.org/cl/6820120 --- src/pkg/runtime/sys_linux_386.s | 24 +++++++++++------------- 1 file changed, 11 insertions(+), 13 deletions(-) (limited to 'src/pkg/runtime/sys_linux_386.s') diff --git a/src/pkg/runtime/sys_linux_386.s b/src/pkg/runtime/sys_linux_386.s index 28ae37b8d9..b212f806c1 100644 --- a/src/pkg/runtime/sys_linux_386.s +++ b/src/pkg/runtime/sys_linux_386.s @@ -104,40 +104,38 @@ TEXT runtime·mincore(SB),7,$0-24 // func now() (sec int64, nsec int32) TEXT time·now(SB), 7, $32 - MOVL $78, AX // syscall - gettimeofday - LEAL 8(SP), BX - MOVL $0, CX + MOVL $265, AX // syscall - clock_gettime + MOVL $0, BX + LEAL 8(SP), CX MOVL $0, DX CALL *runtime·_vdso(SB) MOVL 8(SP), AX // sec - MOVL 12(SP), BX // usec + MOVL 12(SP), BX // nsec - // sec is in AX, usec in BX + // sec is in AX, nsec in BX MOVL AX, sec+0(FP) MOVL $0, sec+4(FP) - IMULL $1000, BX MOVL BX, nsec+8(FP) RET // int64 nanotime(void) so really // void nanotime(int64 *nsec) TEXT runtime·nanotime(SB), 7, $32 - MOVL $78, AX // syscall - gettimeofday - LEAL 8(SP), BX - MOVL $0, CX + MOVL $265, AX // syscall - clock_gettime + MOVL $0, BX + LEAL 8(SP), CX MOVL $0, DX CALL *runtime·_vdso(SB) MOVL 8(SP), AX // sec - MOVL 12(SP), BX // usec + MOVL 12(SP), BX // nsec - // sec is in AX, usec in BX + // sec is in AX, nsec in BX // convert to DX:AX nsec MOVL $1000000000, CX MULL CX - IMULL $1000, BX ADDL BX, AX ADCL $0, DX - + MOVL ret+0(FP), DI MOVL AX, 0(DI) MOVL DX, 4(DI) -- cgit v1.3-5-g9baa