tasksetコマンドを使って特定のCPUコアでプログラムを動かす

README.md

通常

$ go build
$ ./app
GOMAXPROC=12
t1: 0
t1: 1
t1: 2
t1: 3
t1: 4
t2: 0
t3: 0
t3: 1
t3: 2
t3: 3
t3: 4
t2: 1
t2: 2
t2: 3
t2: 4

taskset指定

$ taskset -c 0 ./app
GOMAXPROC=1
t1: 0
t1: 1
t1: 2
t1: 3
t1: 4
t2: 0
t2: 1
t2: 2
t2: 3
t2: 4
t3: 0
t3: 1
t3: 2
t3: 3
t3: 4

main.go

package main

import (
        "fmt"
        "os"
        "runtime"
        "sync"
)

const (
        LOOP_COUNT = 5
)

func init() {
        fmt.Printf("GOMAXPROC=%d\n", runtime.GOMAXPROCS(0))
}

func main() {
        var (
                ch = make(chan string)
                wg = sync.WaitGroup{}
                fn = func(wg *sync.WaitGroup, ch chan<- string, prefix int) {
                        defer wg.Done()
                        for i := 0; i < LOOP_COUNT; i++ {
                                ch <- fmt.Sprintf("t%d: %d", prefix, i)
                        }
                }
        )

        wg.Add(3)

        go fn(&wg, ch, 1)
        go fn(&wg, ch, 2)
        go fn(&wg, ch, 3)

        go func() {
                defer close(ch)
                wg.Wait()
        }()

        for v := range ch {
                fmt.Fprintln(os.Stderr, v)
        }
}