diff --git a/debug/debug.go b/debug/debug.go
deleted file mode 100644
index 1136288c1..000000000
--- a/debug/debug.go
+++ /dev/null
@@ -1,72 +0,0 @@
-/*
-   Copyright The containerd Authors.
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
-
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
-*/
-
-package debug
-
-import (
-	"bufio"
-	"fmt"
-	"os"
-	"strconv"
-	"strings"
-)
-
-// Smaps prints the smaps to a file
-func Smaps(note, file string) error {
-	smaps, err := getMaps(os.Getpid())
-	if err != nil {
-		return err
-	}
-	f, err := os.OpenFile(file, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
-	if err != nil {
-		return err
-	}
-	defer f.Close()
-	fmt.Fprintf(f, "%s: rss %d\n", note, smaps["rss"])
-	fmt.Fprintf(f, "%s: pss %d\n", note, smaps["pss"])
-	return nil
-}
-
-func getMaps(pid int) (map[string]int, error) {
-	f, err := os.Open(fmt.Sprintf("/proc/%d/smaps", pid))
-	if err != nil {
-		return nil, err
-	}
-	defer f.Close()
-	var (
-		smaps = make(map[string]int)
-		s     = bufio.NewScanner(f)
-	)
-	for s.Scan() {
-		var (
-			fields = strings.Fields(s.Text())
-			name   = fields[0]
-		)
-		name = strings.TrimSuffix(strings.ToLower(name), ":")
-		if len(fields) < 2 {
-			continue
-		}
-		n, err := strconv.Atoi(fields[1])
-		if err != nil {
-			continue
-		}
-		smaps[name] += n
-	}
-	if err := s.Err(); err != nil {
-		return nil, err
-	}
-	return smaps, nil
-}