RFR(xxs): 8203032: PrintMetaspaceDcmd fails: 'Non-Class:' missing from stdout/stderr

[Thomas Stüfe]

Hi all,

may I please have reviews for this small fix:

Bug: https://bugs.openjdk.java.net/browse/JDK-8203032

Fix:

diff -r 2f79462aab9b
test/hotspot/jtreg/runtime/Metaspace/PrintMetaspaceDcmd.java
--- a/test/hotspot/jtreg/runtime/Metaspace/PrintMetaspaceDcmd.java
 Mon May 07 09:11:21 2018 +0200
+++ b/test/hotspot/jtreg/runtime/Metaspace/PrintMetaspaceDcmd.java
 Mon May 14 11:46:23 2018 +0200
@@ -33,8 +33,8 @@
  * @library /test/lib
  * @modules java.base/jdk.internal.misc
  *          java.management
- * @run main/othervm -XX:MaxMetaspaceSize=201M -XX:+VerifyMetaspace
-XX:+UseCompressedClassPointers PrintMetaspaceDcmd
with-compressed-class-space
- * @run main/othervm -XX:MaxMetaspaceSize=201M -XX:+VerifyMetaspace
-XX:-UseCompressedClassPointers PrintMetaspaceDcmd
without-compressed-class-space
+ * @run main/othervm -XX:MaxMetaspaceSize=201M -Xmx100M
-XX:+UseCompressedOops -XX:+UseCompressedClassPointers
PrintMetaspaceDcmd with-compressed-class-space
+ * @run main/othervm -XX:MaxMetaspaceSize=201M -Xmx100M
-XX:-UseCompressedOops -XX:-UseCompressedClassPointers
PrintMetaspaceDcmd without-compressed-class-space
  */


There had been two issues:

1) I let the test run with -XX:+VerifyMetaspace, but that one is a
debug only option, so the test fails in release build. Well, that was
just stupid :)

My fix is to just remove the option, since I do not know how to
specify an option for debug VMs only.

2) The test requires the VM to be started with
+UseCompressedClassPointers, and assumed +UseCompressedOops would be
always set, because it is default. However, the test is started with
CompressedOops explicitly turned off. I do not understand why but my
assumtion is that it has to do with -XX:MaxRAMPercentage=8 and running
on a big machine, where 8% of the available RAM would bring the VM
above the max. 32G heapsize needed to have compressed oops.

My fix is to first, specify -XX:+UseCompressedOops explicitly, and
second to limit the max heap size to -Xmx100M. I hope this will
overrule the -XX:MaxRAMPercentage=8 handed down from above? But since
I do not know exactly via which way this option came down, I cannot
reproduce and test. So, I would be obliged if someone could test if
this fix fixes the issues on Oracles tests.


Thanks, Thomas