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author | Martin Möhrmann <moehrmann@google.com> | 2020-10-20 09:56:14 +0200 |
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committer | Martin Möhrmann <moehrmann@google.com> | 2020-10-20 21:30:18 +0000 |
commit | b7a2d413a3f710f14accedf185c93bfb63d24fd0 (patch) | |
tree | 0b742d64de218eae529e71a0c7bbe56119b6bbdc /src/internal | |
parent | 80182d45b5d2ff86da7b6587a2a09d8924dd0a95 (diff) | |
download | go-b7a2d413a3f710f14accedf185c93bfb63d24fd0.tar.gz go-b7a2d413a3f710f14accedf185c93bfb63d24fd0.zip |
testing: print cpu type as label for benchmarks
Supports 386 and amd64 architectures on all operating systems.
Example output:
$ go test -bench=.*
goos: darwin
goarch: amd64
pkg: strconv
cpu: Intel(R) Core(TM) i7-3520M CPU @ 2.90GHz
BenchmarkAtof64Decimal-4 24431032 46.8 ns/op
...
As the displayed CPU information is only used for information
purposes it is lazily initialized when needed using the new
internal/sysinfo package.
This allows internal/cpu to stay without dependencies and avoid
initialization costs when the CPU information is not needed as
the new code to query the CPU name in internal/cpu can be
dead code eliminated if not used.
Fixes #39214
Change-Id: I77ae5c5d2fed6b28fa78dd45075f9f0a6a7f1bfd
Reviewed-on: https://go-review.googlesource.com/c/go/+/263804
Trust: Martin Möhrmann <moehrmann@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Diffstat (limited to 'src/internal')
-rw-r--r-- | src/internal/cpu/cpu_no_name.go | 19 | ||||
-rw-r--r-- | src/internal/cpu/cpu_x86.go | 49 | ||||
-rw-r--r-- | src/internal/sysinfo/sysinfo.go | 31 |
3 files changed, 99 insertions, 0 deletions
diff --git a/src/internal/cpu/cpu_no_name.go b/src/internal/cpu/cpu_no_name.go new file mode 100644 index 0000000000..ce1c37a3c7 --- /dev/null +++ b/src/internal/cpu/cpu_no_name.go @@ -0,0 +1,19 @@ +// Copyright 2020 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build !386 +// +build !amd64 + +package cpu + +// Name returns the CPU name given by the vendor +// if it can be read directly from memory or by CPU instructions. +// If the CPU name can not be determined an empty string is returned. +// +// Implementations that use the Operating System (e.g. sysctl or /sys/) +// to gather CPU information for display should be placed in internal/sysinfo. +func Name() string { + // "A CPU has no name". + return "" +} diff --git a/src/internal/cpu/cpu_x86.go b/src/internal/cpu/cpu_x86.go index da6cf67258..fb414adaf8 100644 --- a/src/internal/cpu/cpu_x86.go +++ b/src/internal/cpu/cpu_x86.go @@ -38,6 +38,8 @@ const ( cpuid_ADX = 1 << 19 ) +var maxExtendedFunctionInformation uint32 + func doinit() { options = []option{ {Name: "adx", Feature: &X86.HasADX}, @@ -65,6 +67,8 @@ func doinit() { return } + maxExtendedFunctionInformation, _, _, _ = cpuid(0x80000000, 0) + _, _, ecx1, edx1 := cpuid(1, 0) X86.HasSSE2 = isSet(edx1, cpuid_SSE2) @@ -103,3 +107,48 @@ func doinit() { func isSet(hwc uint32, value uint32) bool { return hwc&value != 0 } + +// Name returns the CPU name given by the vendor. +// If the CPU name can not be determined an +// empty string is returned. +func Name() string { + if maxExtendedFunctionInformation < 0x80000004 { + return "" + } + + data := make([]byte, 0, 3*4*4) + + var eax, ebx, ecx, edx uint32 + eax, ebx, ecx, edx = cpuid(0x80000002, 0) + data = appendBytes(data, eax, ebx, ecx, edx) + eax, ebx, ecx, edx = cpuid(0x80000003, 0) + data = appendBytes(data, eax, ebx, ecx, edx) + eax, ebx, ecx, edx = cpuid(0x80000004, 0) + data = appendBytes(data, eax, ebx, ecx, edx) + + // Trim leading spaces. + for len(data) > 0 && data[0] == ' ' { + data = data[1:] + } + + // Trim tail after and including the first null byte. + for i, c := range data { + if c == '\x00' { + data = data[:i] + break + } + } + + return string(data) +} + +func appendBytes(b []byte, args ...uint32) []byte { + for _, arg := range args { + b = append(b, + byte((arg >> 0)), + byte((arg >> 8)), + byte((arg >> 16)), + byte((arg >> 24))) + } + return b +} diff --git a/src/internal/sysinfo/sysinfo.go b/src/internal/sysinfo/sysinfo.go new file mode 100644 index 0000000000..961be7abae --- /dev/null +++ b/src/internal/sysinfo/sysinfo.go @@ -0,0 +1,31 @@ +// Copyright 2020 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package sysinfo implements high level hardware information gathering +// that can be used for debugging or information purposes. +package sysinfo + +import ( + internalcpu "internal/cpu" + "sync" +) + +type cpuInfo struct { + once sync.Once + name string +} + +var CPU cpuInfo + +func (cpu *cpuInfo) Name() string { + cpu.once.Do(func() { + // Try to get the information from internal/cpu. + if name := internalcpu.Name(); name != "" { + cpu.name = name + return + } + // TODO(martisch): use /proc/cpuinfo and /sys/devices/system/cpu/ on Linux as fallback. + }) + return cpu.name +} |