8140585: PLAB statistics are flushed too late
Summary: Move the call to G1EvacStats::adjust_desired_plab_sz() to after flushing the per-thread statistics.
Reviewed-by: mgerdin, jmasa
--- a/hotspot/src/share/vm/gc/g1/g1Allocator.cpp Tue Nov 10 04:37:35 2015 +0000
+++ b/hotspot/src/share/vm/gc/g1/g1Allocator.cpp Tue Nov 10 09:29:40 2015 +0100
@@ -110,9 +110,6 @@
if (_retained_old_gc_alloc_region != NULL) {
_retained_old_gc_alloc_region->record_retained_region();
}
-
- _g1h->alloc_buffer_stats(InCSetState::Young)->adjust_desired_plab_sz();
- _g1h->alloc_buffer_stats(InCSetState::Old)->adjust_desired_plab_sz();
}
void G1DefaultAllocator::abandon_gc_alloc_regions() {
--- a/hotspot/src/share/vm/gc/g1/g1CollectedHeap.cpp Tue Nov 10 04:37:35 2015 +0000
+++ b/hotspot/src/share/vm/gc/g1/g1CollectedHeap.cpp Tue Nov 10 09:29:40 2015 +0100
@@ -5210,6 +5210,9 @@
record_obj_copy_mem_stats();
+ _survivor_evac_stats.adjust_desired_plab_sz();
+ _old_evac_stats.adjust_desired_plab_sz();
+
// Reset and re-enable the hot card cache.
// Note the counts for the cards in the regions in the
// collection set are reset when the collection set is freed.
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/gc/g1/TestPLABOutput.java Tue Nov 10 09:29:40 2015 +0100
@@ -0,0 +1,96 @@
+/*
+ * Copyright (c) 2015, 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.
+ */
+
+/*
+ * @test TestPLABOutput
+ * @bug 8140585
+ * @summary Check that G1 does not report empty PLAB statistics in the first evacuation.
+ * @requires vm.gc=="G1" | vm.gc=="null"
+ * @key gc
+ * @library /testlibrary /../../test/lib
+ * @build sun.hotspot.WhiteBox
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ * @run driver TestPLABOutput
+ */
+
+import sun.hotspot.WhiteBox;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import jdk.test.lib.OutputAnalyzer;
+import jdk.test.lib.Platform;
+import jdk.test.lib.ProcessTools;
+
+import static jdk.test.lib.Asserts.*;
+
+public class TestPLABOutput {
+
+ public static void runTest() throws Exception {
+ final String[] arguments = {
+ "-Xbootclasspath/a:.",
+ "-XX:+UnlockExperimentalVMOptions",
+ "-XX:+UnlockDiagnosticVMOptions",
+ "-XX:+WhiteBoxAPI",
+ "-XX:+UseG1GC",
+ "-Xmx10M",
+ "-XX:+PrintGC",
+ "-XX:+PrintPLAB",
+ GCTest.class.getName()
+ };
+
+ ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(arguments);
+ OutputAnalyzer output = new OutputAnalyzer(pb.start());
+
+ output.shouldHaveExitValue(0);
+
+ System.out.println(output.getStdout());
+
+ String pattern = "#0:.*allocated = (\\d+).*";
+ Pattern r = Pattern.compile(pattern);
+ Matcher m = r.matcher(output.getStdout());
+
+ if (!m.find()) {
+ throw new RuntimeException("Could not find any PLAB statistics output");
+ }
+ int allocated = Integer.parseInt(m.group(1));
+ assertGT(allocated, 0, "Did not allocate any memory during test");
+ }
+
+ public static void main(String[] args) throws Exception {
+ runTest();
+ }
+
+ static class GCTest {
+ private static final WhiteBox WB = WhiteBox.getWhiteBox();
+
+ public static Object holder;
+
+ public static void main(String [] args) {
+ holder = new byte[100];
+ WB.youngGC();
+ System.out.println(holder);
+ }
+ }
+}
+