1 // Copyright 2017 The Prometheus Authors
2 // Licensed under the Apache License, Version 2.0 (the "License");
3 // you may not use this file except in compliance with the License.
4 // You may obtain a copy of the License at
6 // http://www.apache.org/licenses/LICENSE-2.0
8 // Unless required by applicable law or agreed to in writing, software
9 // distributed under the License is distributed on an "AS IS" BASIS,
10 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11 // See the License for the specific language governing permissions and
12 // limitations under the License.
25 // A BuddyInfo is the details parsed from /proc/buddyinfo.
26 // The data is comprised of an array of free fragments of each size.
27 // The sizes are 2^n*PAGE_SIZE, where n is the array index.
28 type BuddyInfo struct {
34 // NewBuddyInfo reads the buddyinfo statistics.
35 func NewBuddyInfo() ([]BuddyInfo, error) {
36 fs, err := NewFS(DefaultMountPoint)
41 return fs.NewBuddyInfo()
44 // NewBuddyInfo reads the buddyinfo statistics from the specified `proc` filesystem.
45 func (fs FS) NewBuddyInfo() ([]BuddyInfo, error) {
46 file, err := os.Open(fs.Path("buddyinfo"))
52 return parseBuddyInfo(file)
55 func parseBuddyInfo(r io.Reader) ([]BuddyInfo, error) {
57 buddyInfo = []BuddyInfo{}
58 scanner = bufio.NewScanner(r)
64 line := scanner.Text()
65 parts := strings.Fields(line)
68 return nil, fmt.Errorf("invalid number of fields when parsing buddyinfo")
71 node := strings.TrimRight(parts[1], ",")
72 zone := strings.TrimRight(parts[3], ",")
73 arraySize := len(parts[4:])
75 if bucketCount == -1 {
76 bucketCount = arraySize
78 if bucketCount != arraySize {
79 return nil, fmt.Errorf("mismatch in number of buddyinfo buckets, previous count %d, new count %d", bucketCount, arraySize)
83 sizes := make([]float64, arraySize)
84 for i := 0; i < arraySize; i++ {
85 sizes[i], err = strconv.ParseFloat(parts[i+4], 64)
87 return nil, fmt.Errorf("invalid value in buddyinfo: %s", err)
91 buddyInfo = append(buddyInfo, BuddyInfo{node, zone, sizes})
94 return buddyInfo, scanner.Err()