Poor man regression testing

test/src/test/java/hudson/util/AtomicFileWriterPerfTest.java

+package hudson.util;
+
+import org.junit.ClassRule;
+import org.junit.Test;
+import org.jvnet.hudson.test.Issue;
+import org.jvnet.hudson.test.JenkinsRule;
+
+public class AtomicFileWriterPerfTest {
+
+    @ClassRule
+    public static final JenkinsRule rule = new JenkinsRule();
+
+    /**
+     * This test is meant to catch huge regressions in terms of serialization performance.
+     * <p>
+     * <p>Some data points to explain the timeout value below:</p>
+     * <ul>
+     * <li>On a modern SSD in 2017, it takes less than a second to run.</li>
+     * <li>Using Docker resource constraints, and setting in read&write to IOPS=40 and BPS=10m (i.e. roughly worse than
+     * an old 5400 RPM hard disk), this test takes 25 seconds</li>
+     * </ul>
+     * <p>
+     * So using slightly more than the worse value obtained above should avoid making this flaky and still catch
+     * <strong>really</strong> bad performance regressions.
+     */
+    @Issue("JENKINS-34855")
+    @Test(timeout = 30 * 1000L)
+    public void poorManPerformanceTestBed() throws Exception {
+        int count = 1000;
+        while (count-- > 0) {
+            rule.jenkins.save();
+        }
+    }
+}