Introduce aggregated smap events (enabled by default) (#7820)

* Enable aggregated smap events by default in place of existing smap single entries

* Formatting

* Formatting

* Modify when to use which smap recording mode

* Formatting

* Remove leftover debug print

Author: Matt

dd-java-agent/agent-profiling/profiling-controller-openjdk/src/main/java/com/datadog/profiling/controller/openjdk/OpenJdkController.java

@@ -223,12 +223,17 @@ ProfilingConfig.PROFILING_ALLOCATION_ENABLED, isObjectAllocationSampleAvailable(
       }
     }
 
-    if (configProvider.getBoolean(
+    if (!configProvider.getBoolean(
         ProfilingConfig.PROFILING_SMAP_COLLECTION_ENABLED,
         ProfilingConfig.PROFILING_SMAP_COLLECTION_ENABLED_DEFAULT)) {
-      enableEvent(recordingSettings, "datadog.SmapEntry", "User enabled smaps collection");
-    } else {
       disableEvent(recordingSettings, "datadog.SmapEntry", "User disabled smaps collection");
+    } else if (!configProvider.getBoolean(
+        ProfilingConfig.PROFILING_SMAP_AGGREGATION_ENABLED,
+        ProfilingConfig.PROFILING_SMAP_AGGREGATION_ENABLED_DEFAULT)) {
+      disableEvent(
+          recordingSettings,
+          "datadog.AggregatedSmapEntry",
+          "User disabled aggregated smaps collection");
     }
 
     // Warn users for expensive events

dd-java-agent/agent-profiling/profiling-controller-openjdk/src/main/java/com/datadog/profiling/controller/openjdk/events/AggregatedSmapEntryEvent.java

@@ -0,0 +1,56 @@
+package com.datadog.profiling.controller.openjdk.events;
+
+import java.util.HashMap;
+import java.util.List;
+import jdk.jfr.Category;
+import jdk.jfr.DataAmount;
+import jdk.jfr.Description;
+import jdk.jfr.Event;
+import jdk.jfr.EventType;
+import jdk.jfr.Label;
+import jdk.jfr.Name;
+import jdk.jfr.Period;
+import jdk.jfr.StackTrace;
+
+@Name("datadog.AggregatedSmapEntry")
+@Label("Aggregated Smap Entry")
+@Description("Entry for the entries from the smaps file aggregated by NMT category")
+@Category("Datadog")
+@Period("beginChunk")
+@StackTrace(false)
+public class AggregatedSmapEntryEvent extends Event {
+  @Label("NMT Category")
+  private final String nmtCategory;
+
+  @Label("Resident Set Size")
+  @DataAmount
+  private final long rss;
+
+  public AggregatedSmapEntryEvent(String nmtCategory, long rss) {
+    this.nmtCategory = nmtCategory;
+    this.rss = rss;
+  }
+
+  public static void emit() {
+    if (EventType.getEventType(AggregatedSmapEntryEvent.class).isEnabled()) {
+      HashMap<String, Long> aggregatedSmapEntries = new HashMap<>();
+      List<? extends Event> collectedEvents = SmapEntryFactory.collectEvents();
+      // A single entry should only be expected for the error cases
+      if (collectedEvents.size() > 1) {
+        collectedEvents.forEach(
+            entry -> {
+              aggregatedSmapEntries.merge(
+                  ((SmapEntryEvent) entry).getNmtCategory(),
+                  ((SmapEntryEvent) entry).getRss(),
+                  Long::sum);
+            });
+        aggregatedSmapEntries.forEach(
+            (nmtCategory, rss) -> {
+              new AggregatedSmapEntryEvent(nmtCategory, rss).commit();
+            });
+      } else {
+        collectedEvents.forEach(Event::commit);
+      }
+    }
+  }
+}

dd-java-agent/agent-profiling/profiling-controller-openjdk/src/main/java/com/datadog/profiling/controller/openjdk/events/SmapEntryEvent.java

@@ -3,8 +3,8 @@
 import jdk.jfr.Category;
 import jdk.jfr.DataAmount;
 import jdk.jfr.Description;
-import jdk.jfr.Enabled;
 import jdk.jfr.Event;
+import jdk.jfr.EventType;
 import jdk.jfr.Label;
 import jdk.jfr.Name;
 import jdk.jfr.Period;
@@ -15,7 +15,6 @@
 @Description("Entry from the smaps file for the JVM")
 @Category("Datadog")
 @Period("beginChunk")
-@Enabled
 @StackTrace(false)
 public class SmapEntryEvent extends Event {
 
@@ -241,6 +240,17 @@ public SmapEntryEvent(
   }
 
   public static void emit() {
-    SmapEntryFactory.collectEvents().forEach(Event::commit);
+    if (!EventType.getEventType(AggregatedSmapEntryEvent.class).isEnabled()) {
+      SmapEntryFactory.collectEvents().forEach(Event::commit);
+    } else {
+    }
+  }
+
+  public long getRss() {
+    return this.rss;
+  }
+
+  public String getNmtCategory() {
+    return this.nmtCategory;
   }
 }

dd-java-agent/agent-profiling/profiling-controller-openjdk/src/main/java/com/datadog/profiling/controller/openjdk/events/SmapEntryFactory.java

@@ -60,7 +60,9 @@ public SmapParseErrorEvent(ErrorReason reason) {
   public static void registerEvents() {
     // Make sure the periodic event is registered only once
     if (REGISTERED.compareAndSet(false, true) && Platform.isLinux()) {
+      // Only one of these should ever be enabled at the same time
       JfrHelper.addPeriodicEvent(SmapEntryEvent.class, SmapEntryEvent::emit);
+      JfrHelper.addPeriodicEvent(AggregatedSmapEntryEvent.class, AggregatedSmapEntryEvent::emit);
       try {
         ObjectName objectName = new ObjectName("com.sun.management:type=DiagnosticCommand");
         MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();

dd-trace-api/src/main/java/datadog/trace/api/config/ProfilingConfig.java

@@ -212,6 +212,11 @@ public final class ProfilingConfig {
 
   public static final boolean PROFILING_SMAP_COLLECTION_ENABLED_DEFAULT = true;
 
+  public static final String PROFILING_SMAP_AGGREGATION_ENABLED =
+      "profiling.smap.aggregation.enabled";
+
+  public static final boolean PROFILING_SMAP_AGGREGATION_ENABLED_DEFAULT = true;
+
   public static final String PROFILING_QUEUEING_TIME_THRESHOLD_MILLIS =
       "profiling.queueing.time.threshold.millis";