diff --git a/phymem_plan9.go b/phymem_plan9.go
index cd56e34..4fccede 100644
--- a/phymem_plan9.go
+++ b/phymem_plan9.go
@@ -1,12 +1,9 @@
 package phymem
 
 import (
-	"errors"
-	"fmt"
-	"io"
 	"os"
-	"strconv"
-	"strings"
+
+	"github.com/koron-go/phymem/internal/procstatus"
 )
 
 // for test.
@@ -14,44 +11,5 @@ const providedCurrent = true
 
 // Current get physical memory which used by current process.
 func Current() (uint, error) {
-	name := fmt.Sprintf("/proc/%d/status", os.Getpid())
-	r, err := os.Open(name)
-	if err != nil {
-		return 0, err
-	}
-	defer r.Close()
-	return readMemSize(r)
-}
-
-func readMemSize(r io.Reader) (uint, error) {
-	/*
-	 * proc/<n>/status contains process's status separated by a space.
-	 * 1. [27]the process name
-	 * 2. [27]the user name
-	 * 3. [11]the process status
-	 * 4. [11]the time current process has spent in user mode (ms)
-	 * 5. [11]the time current process has spent in system calls (ms)
-	 * 6. [11]the time current process has spent in real elapsed time (ms)
-	 * 7. [11]the time children and descendants's; user mode (ms)
-	 * 8. [11]the time children and descendants's; system calls (ms)
-	 * 9. [11]the time children and descendants's; real elapsed time (ms)
-	 * 10. [11]the amount of memory (kb)
-	 * 11. [11]the base scheduling priority
-	 * 12. [11]the current scheduling priority
-	 */
-	buf := make([]byte, (27+1)*2+(11+1)*10) // +1: a space
-	n, err := r.Read(buf)
-	if err != nil {
-		return 0, err
-	}
-	if n != len(buf) {
-		return 0, errors.New("insufficient process status")
-	}
-	p := (27+1)*2 + (11+1)*7
-	s := strings.TrimSpace(string(buf[p : p+11]))
-	msize, err := strconv.ParseUint(s, 10, 32)
-	if err != nil {
-		return 0, err
-	}
-	return uint(msize) * 1024, nil
+	return procstatus.GetRSS(os.Getpid())
 }