Merge pull request #106 from retronym/topic/jmh-snapshot

Use JMH's first party support for JFR Profiler

Author: retronym

build.sbt

@@ -96,12 +96,15 @@ addCommandAlias("cold", "compilation/jmh:run ColdScalacBenchmark -foe true")
 
 commands ++= build.Profiler.commands
 
+// duplicated in project/build.sbt
+val jmhV = "1.25"
+
 def addJmh(project: Project): Project = {
   // IntelliJ SBT project import doesn't like sbt-jmh's default setup, which results the prod and test
   // output paths overlapping. This is because sbt-jmh declares the `jmh` config as extending `test`, but
   // configures `classDirectory in Jmh := classDirectory in Compile`.
   project.enablePlugins(JmhPlugin).overrideConfigs(JmhConfig.extend(Compile)).settings(
-    version in Jmh := "1.24" // duplicated in project/build.sbt
+    version in Jmh := jmhV
   )
 }
 

infrastructure/src/main/java/scala/bench/JfrToFlamegraph.java

@@ -0,0 +1,120 @@
+package scala.bench;
+
+import org.openjdk.jmh.infra.BenchmarkParams;
+import org.openjdk.jmh.profile.JavaFlightRecorderProfiler;
+import org.openjdk.jmh.util.InputStreamDrainer;
+import org.openjdk.jmh.util.Utils;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.*;
+import java.util.stream.Collectors;
+
+public final class JfrToFlamegraph implements JavaFlightRecorderProfiler.PostProcessor {
+  private static final Path JFR_FLAMEGRAPH_DIR = findJfrFlamegraph();
+  private static final Path FLAMEGRAPH_DIR = findFlamegraphDir();
+  private enum Direction {
+    FORWARD,
+    REVERSE
+  }
+
+  public List<File> postProcess(BenchmarkParams benchmarkParams, File jfrFile) {
+    ArrayList<File> generated = new ArrayList<>();
+    List<String> events = Arrays.asList("cpu", "allocation-tlab", "allocation-outside-tlab");
+    if (JFR_FLAMEGRAPH_DIR != null) {
+      for (String event : events) {
+        Path csvFile = createCollapsed(event, jfrFile.toPath());
+        generated.add(csvFile.toFile());
+        if (FLAMEGRAPH_DIR != null) {
+          for (Direction direction : EnumSet.allOf(Direction.class)) {
+            Path svgPath = flameGraph(csvFile, Arrays.asList(), direction, Arrays.asList());
+            generated.add(svgPath.toFile());
+          }
+        }
+      }
+    }
+    return generated;
+  }
+
+  private Path createCollapsed(String eventName, Path jfrFile) {
+    ArrayList<String> args = new ArrayList<>();
+    args.add("bash");
+    args.add("-e");
+    args.add(JFR_FLAMEGRAPH_DIR.toAbsolutePath().toString());
+    args.add("--output-type");
+    args.add("folded");
+    args.add("--jfrdump");
+    args.add(jfrFile.toAbsolutePath().toString());
+    args.add("--event");
+    args.add(eventName);
+    Path outFile = jfrFile.resolveSibling(jfrFile.getFileName().toString().replace(".jfr", "-" + eventName.toLowerCase() + ".csv"));
+    args.add("--output");
+    args.add(outFile.toString());
+    Collection<String> errorOutput = Utils.tryWith(args.toArray(new String[0]));
+    if (errorOutput.isEmpty()) {
+      return outFile;
+    } else {
+      throw new RuntimeException("Error in :" + args.stream().collect(Collectors.joining(" ")), new RuntimeException("Failed to convert JFR to CSV: " + errorOutput.stream().collect(Collectors.joining(System.lineSeparator()) )));
+    }
+  }
+
+  private static Path findJfrFlamegraph() {
+    Path jfrFlameGraphDir = Paths.get(System.getenv("JFR_FLAME_GRAPH_DIR"));
+    Path script = jfrFlameGraphDir.resolve("jfr-flame-graph");
+    if (!Files.exists(script)) {
+      script = jfrFlameGraphDir.resolve("build/install/jfr-flame-graph/bin/jfr-flame-graph");
+    }
+    if (!Files.exists(script)) {
+      return null;
+    } else {
+      return script.toAbsolutePath();
+    }
+  }
+
+  private static Path flameGraph(Path collapsedPath, List<String> extra, Direction direction, Collection<? extends String> flameGraphOptions) {
+    ArrayList<String> args = new ArrayList<>();
+    args.add("perl");
+    args.add(FLAMEGRAPH_DIR.resolve("flamegraph.pl").toAbsolutePath().toString());
+    args.addAll(flameGraphOptions);
+    args.addAll(extra);
+    if (direction == Direction.REVERSE) {
+      args.add("--reverse");
+    }
+    args.addAll(Arrays.asList("--minwidth", "1", "--colors", "java", "--cp", "--width", "1800"));
+    args.add(collapsedPath.toAbsolutePath().toString());
+    Path outputFile = collapsedPath.resolveSibling(collapsedPath.getFileName().toString().replace(".csv", "-" + direction.name().toLowerCase() + ".svg"));
+    ProcessBuilder processBuilder = new ProcessBuilder(args);
+    processBuilder.redirectOutput(outputFile.toFile());
+    try {
+      Process p = processBuilder.start();
+      ByteArrayOutputStream baos = new ByteArrayOutputStream();
+      InputStreamDrainer errDrainer = new InputStreamDrainer(p.getErrorStream(), baos);
+      InputStreamDrainer outDrainer = new InputStreamDrainer(p.getInputStream(), baos);
+      int err = p.waitFor();
+      errDrainer.start();
+      outDrainer.start();
+      errDrainer.join();
+      outDrainer.join();
+      if (err != 0) {
+        throw new RuntimeException("Non zero return code from " + args + System.lineSeparator() + baos.toString());
+      }
+    } catch (IOException | InterruptedException e) {
+      throw new RuntimeException(e);
+    }
+    return outputFile;
+  }
+
+
+  private static Path findFlamegraphDir() {
+    String flameGraphHome = System.getenv("FLAME_GRAPH_DIR");
+    if (flameGraphHome == null) {
+      return null;
+    } else {
+      return Paths.get(flameGraphHome);
+    }
+  }
+}

project/Profilers.scala

@@ -35,17 +35,17 @@ case object basic extends Profiler("basic") {
   def command(outDir: File): String = "-jvmArgs -Xprof -prof hs_comp -prof gc -prof stack -prof hs_rt -prof scala.tools.nsc.ThreadCpuTimeProfiler"
 }
 case object jfr extends Profiler("jfr") {
-  def command(outDir: File): String = s"""-prof "jmh.extras.JFR:dir=${outDir.getAbsolutePath};flameGraphOpts=$flameGraphOpts;verbose=true" """
+  def command(outDir: File): String = s"""-prof "jfr:dir=${outDir.getAbsolutePath};stackDepth=1024;postProcessor=scala.bench.JfrToFlamegraph;verbose=true" """
 }
 sealed abstract class async(event: String) extends Profiler("async-" + event) {
   val framebuf = 33554432
   def command(outDir: File): String = {
-    s"""-prof "async:dir=${outDir.getAbsolutePath};libPath=${System.getenv("ASYNC_PROFILER_DIR")}/build/libasyncProfiler.so;minwidth=1;width=1800;verbose=true;event=$event;filter=${event == "wall"};flat=40;trace=10;framebuf=${framebuf};output=flamegraph,jfr,text" """
+    s"""-prof -jvmArgs -XX:+UnlockCommercialFeatures "async:dir=${outDir.getAbsolutePath};libPath=${System.getenv("ASYNC_PROFILER_DIR")}/build/libasyncProfiler.so;minwidth=1;width=1800;verbose=true;event=$event;filter=${event == "wall"};flat=40;trace=10;framebuf=${framebuf};output=flamegraph,jfr,text" """
   } // + ";simplename=true" TODO add this after upgrading next sbt-jmh release
 }
 case object asyncCpu extends async("cpu")
 case object asyncAlloc extends async("alloc")
 case object asyncWall extends async("wall")
 case object perfNorm extends Profiler("perfNorm") {
   def command(outDir: File): String = "-prof perfnorm"
-}
+}

project/build.sbt

@@ -1,4 +1,4 @@
-val jmhV = "1.24" // duplicated in build.sbt
+val jmhV = "1.25" // duplicated in build.sbt
 
 libraryDependencies ++= List(
   "org.openjdk.jmh"     % "jmh-core"                 % jmhV,