Eric Caspole 239760ac09 8355233: Add a DMB related benchmark
Reviewed-by: kvn
2025-04-22 19:59:41 +00:00

108 lines
3.2 KiB
Java

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package org.openjdk.bench.vm.compiler;
import java.util.concurrent.TimeUnit;
import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.CompilerControl;
import org.openjdk.jmh.annotations.Fork;
import org.openjdk.jmh.annotations.Group;
import org.openjdk.jmh.annotations.GroupThreads;
import org.openjdk.jmh.annotations.Measurement;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OperationsPerInvocation;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Param;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.Setup;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.annotations.Warmup;
import org.openjdk.jmh.infra.Blackhole;
@BenchmarkMode(Mode.Throughput)
@State(Scope.Benchmark)
@OutputTimeUnit(TimeUnit.MICROSECONDS)
@Warmup(iterations = 8, time = 4)
@Measurement(iterations = 6, time = 3)
public class DMBCheck {
// The allocations of DoubleDMB$A and DoubleDMB$C
// will cause aarch64 dmb barrier instructions.
// The different latency of the dmb ish/ishst/ishld modes
// may make a noticeable difference in the benchmark results.
// These modes may be set by cpu defaults or XX options.
class A {
final String b = new String("Hi there");
}
class C {
private A a;
public A getA() {
if (a == null) {
a = new A();
}
return a;
}
}
static C c = null;
@Setup
public void setup() {
c = new C();
}
@CompilerControl(CompilerControl.Mode.DONT_INLINE)
void action(Blackhole b) throws Exception {
c = new C();
if (c.getA().b == null) {
throw new Exception("a should not be null");
}
b.consume(c);
}
@Benchmark
@Fork(value = 1, jvmArgs = {
"-XX:+UnlockDiagnosticVMOptions", "-XX:+AlwaysMergeDMB", "-XX:+IgnoreUnrecognizedVMOptions"})
public void plusAlwaysMergeDMB(Blackhole b) throws Exception {
action(b);
}
@Benchmark
@Fork(value = 1, jvmArgs = {
"-XX:+UnlockDiagnosticVMOptions", "-XX:-AlwaysMergeDMB", "-XX:+IgnoreUnrecognizedVMOptions"})
public void minusAlwaysMergeDMB(Blackhole b) throws Exception {
action(b);
}
}