1 /*
2 * Copyright (c) 2020, Red Hat Inc.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk.internal.platform;
27
28 import java.io.IOException;
29 import java.lang.System.Logger;
30 import java.lang.System.Logger.Level;
31 import java.nio.file.Paths;
32 import java.util.HashMap;
33 import java.util.List;
34 import java.util.Map;
35 import java.util.stream.Stream;
36
37 import jdk.internal.platform.cgroupv1.CgroupV1Subsystem;
38 import jdk.internal.platform.cgroupv2.CgroupV2Subsystem;
39
40 public class CgroupSubsystemFactory {
41
42 private static final String CPU_CTRL = "cpu";
43 private static final String CPUACCT_CTRL = "cpuacct";
44 private static final String CPUSET_CTRL = "cpuset";
45 private static final String BLKIO_CTRL = "blkio";
46 private static final String MEMORY_CTRL = "memory";
47
48 static CgroupMetrics create() {
49 CgroupTypeResult result = null;
50 try {
51 result = determineType("/proc/self/mountinfo", "/proc/cgroups");
52 } catch (IOException e) {
53 return null;
54 }
55
56 // If no controller is enabled, return no metrics.
57 if (!result.isAnyControllersEnabled()) {
58 return null;
59 }
60 // Warn about mixed cgroups v1 and cgroups v2 controllers. The code is
61 // not ready to deal with that on a per-controller basis. Return no metrics
62 // in that case
63 if (result.isAnyCgroupV1Controllers() && result.isAnyCgroupV2Controllers()) {
64 Logger logger = System.getLogger("jdk.internal.platform");
65 logger.log(Level.DEBUG, "Mixed cgroupv1 and cgroupv2 not supported. Metrics disabled.");
66 return null;
67 }
68
69 if (result.isCgroupV2()) {
70 CgroupSubsystem subsystem = CgroupV2Subsystem.getInstance();
71 return subsystem != null ? new CgroupMetrics(subsystem) : null;
72 } else {
73 CgroupV1Subsystem subsystem = CgroupV1Subsystem.getInstance();
74 return subsystem != null ? new CgroupV1MetricsImpl(subsystem) : null;
75 }
76 }
77
78 public static CgroupTypeResult determineType(String mountInfo, String cgroups) throws IOException {
79 Map<String, CgroupInfo> infos = new HashMap<>();
80 List<String> lines = CgroupUtil.readAllLinesPrivileged(Paths.get(cgroups));
81 for (String line : lines) {
82 if (line.startsWith("#")) {
83 continue;
84 }
85 CgroupInfo info = CgroupInfo.fromCgroupsLine(line);
86 switch (info.getName()) {
87 case CPU_CTRL: infos.put(CPU_CTRL, info); break;
88 case CPUACCT_CTRL: infos.put(CPUACCT_CTRL, info); break;
89 case CPUSET_CTRL: infos.put(CPUSET_CTRL, info); break;
90 case MEMORY_CTRL: infos.put(MEMORY_CTRL, info); break;
91 case BLKIO_CTRL: infos.put(BLKIO_CTRL, info); break;
92 }
93 }
94 Stream<String> mntInfo = CgroupUtil.readFilePrivileged(Paths.get(mountInfo));
95 boolean anyCgroupMounted = mntInfo.anyMatch(line -> line.contains("cgroup"));
96
97 // For cgroups v2 all controllers need to have zero hierarchy id
98 // and /proc/self/mountinfo needs to have at least one cgroup filesystem
99 // mounted.
100 boolean isCgroupsV2 = true;
101 boolean anyControllersEnabled = false;
102 boolean anyCgroupsV2Controller = false;
103 boolean anyCgroupsV1Controller = false;
104 for (CgroupInfo info: infos.values()) {
105 anyCgroupsV1Controller = anyCgroupsV1Controller || info.getHierarchyId() != 0;
106 anyCgroupsV2Controller = anyCgroupsV2Controller || info.getHierarchyId() == 0;
107 isCgroupsV2 = isCgroupsV2 && info.getHierarchyId() == 0;
108 anyControllersEnabled = anyControllersEnabled || info.isEnabled();
109 }
110
111 // If there are no mounted controllers in mountinfo, but we've only
112 // seen 0 hierarchy IDs in /proc/cgroups, we are on a cgroups v1 system.
113 if (!anyCgroupMounted && isCgroupsV2) {
114 isCgroupsV2 = false;
115 anyCgroupsV1Controller = true;
116 anyCgroupsV2Controller = false;
117 }
118 return new CgroupTypeResult(isCgroupsV2, anyControllersEnabled, anyCgroupsV2Controller, anyCgroupsV1Controller);
119 }
120
121 public static final class CgroupTypeResult {
122 private final boolean isCgroupV2;
123 private final boolean anyControllersEnabled;
124 private final boolean anyCgroupV2Controllers;
125 private final boolean anyCgroupV1Controllers;
126
127 private CgroupTypeResult(boolean isCgroupV2,
128 boolean anyControllersEnabled,
129 boolean anyCgroupV2Controllers,
130 boolean anyCgroupV1Controllers) {
131 this.isCgroupV2 = isCgroupV2;
132 this.anyControllersEnabled = anyControllersEnabled;
133 this.anyCgroupV1Controllers = anyCgroupV1Controllers;
134 this.anyCgroupV2Controllers = anyCgroupV2Controllers;
135 }
136
137 public boolean isCgroupV2() {
138 return isCgroupV2;
139 }
140
141 public boolean isAnyControllersEnabled() {
142 return anyControllersEnabled;
143 }
144
145 public boolean isAnyCgroupV2Controllers() {
146 return anyCgroupV2Controllers;
147 }
148
149 public boolean isAnyCgroupV1Controllers() {
150 return anyCgroupV1Controllers;
151 }
152 }
153 }