init.go

package prof

import (
	"code.google.com/p/mx3/util"
	"flag"
	"io/ioutil"
	"log"
	"os"
	"os/exec"
	"runtime/pprof"
)

var (
	Flag_cpuprof = flag.Bool("cpuprof", false, "Record gopprof CPU profile")
	Flag_memprof = flag.Bool("memprof", false, "Recored gopprof memory profile")
	Flag_gpuprof = flag.Bool("gpuprof", false, "Recored GPU profile")
)

func Init(OD string) {
	initGPUProf(OD) // should be before initGPU
	initCpuProf(OD)
	initMemProf(OD)
}

func initCpuProf(OD string) {
	if *Flag_cpuprof {
		// start CPU profile to file
		fname := OD + "cpu.pprof"
		f, err := os.Create(fname)
		util.FatalErr(err, "CPU profile")
		err = pprof.StartCPUProfile(f)
		util.FatalErr(err, "CPU profile")
		log.Println("writing CPU profile to", fname)

		// at exit: exec go tool pprof to generate SVG output
		AtExit(func() {
			pprof.StopCPUProfile()
			me := procSelfExe()
			outfile := fname + ".svg"
			saveCmdOutput(outfile, "go", "tool", "pprof", "-svg", me, fname)
		})
	}
}

func initMemProf(OD string) {
	if *Flag_memprof {
		log.Println("memory profile enabled")
		AtExit(func() {
			fname := OD + "mem.pprof"
			f, err := os.Create(fname)
			defer f.Close()
			util.LogErr(err, "memory profile") // during cleanup, should not panic/exit
			log.Println("writing memory profile to", fname)
			util.LogErr(pprof.WriteHeapProfile(f), "memory profile")
			me := procSelfExe()
			outfile := fname + ".svg"
			saveCmdOutput(outfile, "go", "tool", "pprof", "-svg", "--inuse_objects", me, fname)
		})
	}
}

// Configuration for GPU profile output.
const CUDA_PROFILE_CONFIG = `
gpustarttimestamp
instructions
streamid
`

// called by init()
func initGPUProf(OD string) {
	if *Flag_gpuprof {
		util.PanicErr(os.Setenv("CUDA_PROFILE", "1"))
		util.PanicErr(os.Setenv("CUDA_PROFILE_CSV", "1"))
		out := OD + "gpuprofile.csv"
		log.Println("writing GPU profile to", out)
		util.PanicErr(os.Setenv("CUDA_PROFILE_LOG", out))
		cfgfile := OD + "cudaprof.cfg"
		util.PanicErr(os.Setenv("CUDA_PROFILE_CONFIG", cfgfile))
		util.FatalErr(ioutil.WriteFile(cfgfile, []byte(CUDA_PROFILE_CONFIG), 0666), "gpuprof")
		//AtExit(cuda.DeviceReset)
	}
}

// Exec command and write output to outfile.
func saveCmdOutput(outfile string, cmd string, args ...string) {
	log.Println("exec:", cmd, args, ">", outfile)
	out, err := exec.Command(cmd, args...).Output() // TODO: stderr is ignored
	if err != nil {
		log.Printf("exec %v %v: %v: %v", cmd, args, err, string(out))
	}
	// on error: write anyway, clobbers output file.
	e := ioutil.WriteFile(outfile, out, 0666)
	util.LogErr(e, "writing", outfile)
}

// path to the executable.
func procSelfExe() string {
	me, err := os.Readlink("/proc/self/exe")
	util.PanicErr(err)
	return me
}