8247469: getSystemCpuLoad() returns -1 on linux when some offline cpus are present and cpusets.effective_cpus is not available

Backport-of: 3341d36

Author: jerboaa

src/jdk.management/aix/native/libmanagement_ext/UnixOperatingSystem.c

@@ -1,6 +1,6 @@
 /*
- * Copyright (c) 2008, 2019, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2015 SAP SE. All rights reserved.
+ * Copyright (c) 2008, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2020 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -57,3 +57,10 @@ Java_com_sun_management_internal_OperatingSystemImpl_getHostConfiguredCpuCount0
 {
     return -1;
 }
+
+JNIEXPORT jint JNICALL
+Java_com_sun_management_internal_OperatingSystemImpl_getHostOnlineCpuCount0
+(JNIEnv *env, jobject mbean)
+{
+    return -1;
+}

src/jdk.management/linux/native/libmanagement_ext/UnixOperatingSystem.c

@@ -364,3 +364,15 @@ Java_com_sun_management_internal_OperatingSystemImpl_getHostConfiguredCpuCount0
        return -1;
     }
 }
+
+JNIEXPORT jint JNICALL
+Java_com_sun_management_internal_OperatingSystemImpl_getHostOnlineCpuCount0
+(JNIEnv *env, jobject mbean)
+{
+    int n = sysconf(_SC_NPROCESSORS_ONLN);
+    if (n <= 0) {
+        n = 1;
+    }
+    return n;
+}
+

src/jdk.management/macosx/native/libmanagement_ext/UnixOperatingSystem.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -173,3 +173,11 @@ Java_com_sun_management_internal_OperatingSystemImpl_getHostConfiguredCpuCount0
 {
     return -1;
 }
+
+JNIEXPORT jint JNICALL
+Java_com_sun_management_internal_OperatingSystemImpl_getHostOnlineCpuCount0
+(JNIEnv *env, jobject mbean)
+{
+    return -1;
+}
+

src/jdk.management/unix/classes/com/sun/management/internal/OperatingSystemImpl.java

@@ -158,6 +158,10 @@ public double getSystemCpuLoad() {
                     return getSystemCpuLoad0();
                 } else {
                     int[] cpuSet = containerMetrics.getEffectiveCpuSetCpus();
+                    // in case the effectiveCPUSetCpus are not available, attempt to use just cpusets.cpus
+                    if (cpuSet == null || cpuSet.length <= 0) {
+                        cpuSet = containerMetrics.getCpuSetCpus();
+                    }
                     if (cpuSet != null && cpuSet.length > 0) {
                         double systemLoad = 0.0;
                         for (int cpu : cpuSet) {
@@ -182,7 +186,7 @@ public double getProcessCpuLoad() {
 
     private boolean isCpuSetSameAsHostCpuSet() {
         if (containerMetrics != null) {
-            return containerMetrics.getCpuSetCpus().length == getHostConfiguredCpuCount0();
+            return containerMetrics.getCpuSetCpus().length == getHostOnlineCpuCount0();
         }
         return false;
     }
@@ -200,6 +204,7 @@ private boolean isCpuSetSameAsHostCpuSet() {
     private native long getTotalSwapSpaceSize0();
     private native double getSingleCpuLoad0(int cpuNum);
     private native int getHostConfiguredCpuCount0();
+    private native int getHostOnlineCpuCount0();
 
     static {
         initialize0();