8324287: Record total and free swap space in JFR

Reviewed-by: jbechberger, lucy, egahlin

src/hotspot/os/aix/os_aix.cpp

@@ -273,6 +273,22 @@ julong os::Aix::available_memory() {
   }
 }
 
+jlong os::total_swap_space() {
+  perfstat_memory_total_t memory_info;
+  if (libperfstat::perfstat_memory_total(NULL, &memory_info, sizeof(perfstat_memory_total_t), 1) == -1) {
+    return -1;
+  }
+  return (jlong)(memory_info.pgsp_total * 4 * K);
+}
+
+jlong os::free_swap_space() {
+  perfstat_memory_total_t memory_info;
+  if (libperfstat::perfstat_memory_total(NULL, &memory_info, sizeof(perfstat_memory_total_t), 1) == -1) {
+    return -1;
+  }
+  return (jlong)(memory_info.pgsp_free * 4 * K);
+}
+
 julong os::physical_memory() {
   return Aix::physical_memory();
 }

src/hotspot/os/bsd/os_bsd.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2024, 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
@@ -181,6 +181,32 @@ void os::Bsd::print_uptime_info(outputStream* st) {
   }
 }
 
+jlong os::total_swap_space() {
+#if defined(__APPLE__)
+  struct xsw_usage vmusage;
+  size_t size = sizeof(vmusage);
+  if (sysctlbyname("vm.swapusage", &vmusage, &size, NULL, 0) != 0) {
+    return -1;
+  }
+  return (jlong)vmusage.xsu_total;
+#else
+  return -1;
+#endif
+}
+
+jlong os::free_swap_space() {
+#if defined(__APPLE__)
+  struct xsw_usage vmusage;
+  size_t size = sizeof(vmusage);
+  if (sysctlbyname("vm.swapusage", &vmusage, &size, NULL, 0) != 0) {
+    return -1;
+  }
+  return (jlong)vmusage.xsu_avail;
+#else
+  return -1;
+#endif
+}
+
 julong os::physical_memory() {
   return Bsd::physical_memory();
 }

src/hotspot/os/linux/os_linux.cpp

@@ -289,6 +289,34 @@ julong os::Linux::free_memory() {
   return free_mem;
 }
 
+jlong os::total_swap_space() {
+  if (OSContainer::is_containerized()) {
+    if (OSContainer::memory_limit_in_bytes() > 0) {
+      return (jlong)(OSContainer::memory_and_swap_limit_in_bytes() - OSContainer::memory_limit_in_bytes());
+    }
+  }
+  struct sysinfo si;
+  int ret = sysinfo(&si);
+  if (ret != 0) {
+    return -1;
+  }
+  return  (jlong)(si.totalswap * si.mem_unit);
+}
+
+jlong os::free_swap_space() {
+  if (OSContainer::is_containerized()) {
+    // TODO add a good implementation
+    return -1;
+  } else {
+    struct sysinfo si;
+    int ret = sysinfo(&si);
+    if (ret != 0) {
+      return -1;
+    }
+    return (jlong)(si.freeswap * si.mem_unit);
+  }
+}
+
 julong os::physical_memory() {
   jlong phys_mem = 0;
   if (OSContainer::is_containerized()) {

src/hotspot/os/windows/os_windows.cpp

@@ -840,6 +840,20 @@ julong os::win32::available_memory() {
   return (julong)ms.ullAvailPhys;
 }
 
+jlong os::total_swap_space() {
+  MEMORYSTATUSEX ms;
+  ms.dwLength = sizeof(ms);
+  GlobalMemoryStatusEx(&ms);
+  return (jlong) ms.ullTotalPageFile;
+}
+
+jlong os::free_swap_space() {
+  MEMORYSTATUSEX ms;
+  ms.dwLength = sizeof(ms);
+  GlobalMemoryStatusEx(&ms);
+  return (jlong) ms.ullAvailPageFile;
+}
+
 julong os::physical_memory() {
   return win32::physical_memory();
 }

src/hotspot/share/jfr/metadata/metadata.xml

@@ -927,6 +927,11 @@
     <Field type="ulong" contentType="bytes" name="usedSize" label="Used Size" description="Total amount of physical memory in use" />
   </Event>
 
+  <Event name="SwapSpace" category="Operating System, Memory" label="Swap Space" description="OS Swap Space" period="everyChunk">
+    <Field type="long" contentType="bytes" name="totalSize" label="Total Size" description="Total swap space available to the OS" />
+    <Field type="long" contentType="bytes" name="freeSize" label="Free Size" description="Free swap space" />
+  </Event>
+
   <Event name="ExecutionSample" category="Java Virtual Machine, Profiling" label="Method Profiling Sample" description="Snapshot of a threads state"
     period="everyChunk">
     <Field type="Thread" name="sampledThread" label="Thread" />

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp

@@ -527,6 +527,13 @@ TRACE_REQUEST_FUNC(PhysicalMemory) {
   event.commit();
 }
 
+TRACE_REQUEST_FUNC(SwapSpace) {
+  EventSwapSpace event;
+  event.set_totalSize(os::total_swap_space());
+  event.set_freeSize(os::free_swap_space());
+  event.commit();
+}
+
 TRACE_REQUEST_FUNC(JavaThreadStatistics) {
   EventJavaThreadStatistics event;
   event.set_activeCount(ThreadService::get_live_thread_count());

src/hotspot/share/runtime/os.hpp

@@ -328,6 +328,9 @@ class os: AllStatic {
   static julong available_memory();
   static julong free_memory();
 
+  static jlong total_swap_space();
+  static jlong free_swap_space();
+
   static julong physical_memory();
   static bool has_allocatable_memory_limit(size_t* limit);
   static bool is_server_class_machine();

src/jdk.jfr/share/conf/jfr/default.jfc

@@ -678,6 +678,11 @@
       <setting name="period">everyChunk</setting>
     </event>
 
+    <event name="jdk.SwapSpace">
+      <setting name="enabled">true</setting>
+      <setting name="period">everyChunk</setting>
+    </event>
+
     <event name="jdk.ObjectAllocationInNewTLAB">
       <setting name="enabled" control="gc-enabled-high">false</setting>
       <setting name="stackTrace">true</setting>

src/jdk.jfr/share/conf/jfr/profile.jfc

@@ -678,6 +678,11 @@
       <setting name="period">everyChunk</setting>
     </event>
 
+    <event name="jdk.SwapSpace">
+      <setting name="enabled">true</setting>
+      <setting name="period">everyChunk</setting>
+    </event>
+
     <event name="jdk.ObjectAllocationInNewTLAB">
       <setting name="enabled" control="gc-enabled-high">false</setting>
       <setting name="stackTrace">true</setting>

test/jdk/jdk/jfr/event/os/TestSwapSpaceEvent.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2013, 2024, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.jfr.event.os;
+
+import java.util.List;
+
+import jdk.jfr.Recording;
+import jdk.jfr.consumer.RecordedEvent;
+import jdk.test.lib.jfr.EventNames;
+import jdk.test.lib.jfr.Events;
+
+/**
+ * @test
+ * @key jfr
+ * @requires vm.hasJFR
+ * @requires (os.family != "linux")
+ * @library /test/lib
+ * @run main/othervm jdk.jfr.event.os.TestSwapSpaceEvent
+ */
+
+/**
+ * @test
+ * @key jfr
+ * @requires vm.hasJFR
+ * @requires (os.family == "linux")
+ * @library /test/lib
+ * @run main/othervm -XX:-UseContainerSupport jdk.jfr.event.os.TestSwapSpaceEvent
+ */
+public class TestSwapSpaceEvent {
+    private final static String EVENT_NAME = EventNames.SwapSpace;
+
+    public static void main(String[] args) throws Throwable {
+        Recording recording = new Recording();
+        recording.enable(EVENT_NAME);
+        recording.start();
+        recording.stop();
+        List<RecordedEvent> events = Events.fromRecording(recording);
+        Events.hasEvents(events);
+        for (RecordedEvent event : events) {
+            System.out.println("Event: " + event);
+            long totalSize = Events.assertField(event, "totalSize").atLeast(0L).getValue();
+            Events.assertField(event, "freeSize").atLeast(0L);
+            Events.assertField(event, "freeSize").atMost(totalSize);
+        }
+    }
+}

test/lib/jdk/test/lib/jfr/EventNames.java

@@ -186,6 +186,7 @@ public class EventNames {
     public static final String NativeLibraryLoad = PREFIX + "NativeLibraryLoad";
     public static final String NativeLibraryUnload = PREFIX + "NativeLibraryUnload";
     public static final String PhysicalMemory = PREFIX + "PhysicalMemory";
+    public static final String SwapSpace = PREFIX + "SwapSpace";
     public static final String NetworkUtilization = PREFIX + "NetworkUtilization";
     public static final String ProcessStart = PREFIX + "ProcessStart";
     public static final String ResidentSetSize = PREFIX + "ResidentSetSize";