RFR (XS) 8215329: Modify ZGC requirement for HeapMonitorThreadTest.java

[Per Liden]

Hi JC,

What's the reason to exclude ZGC from this test to begin with? From what 
I can tell, it's because the test is using a slightly too small heap, or 
are there some other reason? I ran it a few times using various heap 
sizes and the test passes with ZGC when using anything above 612M. So if 
we instead just dump the heap size a bit, then we get test coverage with 
ZGC too. I picked 768M here to have some headroom in case the exact 
limit is run-to-run dependent.

diff --git 
a/test/hotspot/jtreg/serviceability/jvmti/HeapMonitor/MyPackage/HeapMonitorThreadTest.java 
b/test/hotspot/jtreg/serviceability/jvmti/HeapMonitor/MyPackage/HeapMonitorThreadTest.java
--- 
a/test/hotspot/jtreg/serviceability/jvmti/HeapMonitor/MyPackage/HeapMonitorThreadTest.java
+++ 
b/test/hotspot/jtreg/serviceability/jvmti/HeapMonitor/MyPackage/HeapMonitorThreadTest.java
@@ -29,8 +29,7 @@
   * @build Frame HeapMonitor ThreadInformation
   * @summary Verifies the JVMTI Heap Monitor Thread information sanity.
   * @compile HeapMonitorThreadTest.java
- * @run main/othervm/native -Xmx512m -agentlib:HeapMonitorTest 
MyPackage.HeapMonitorThreadTest
- * @requires !vm.gc.Z
+ * @run main/othervm/native -Xmx768m -agentlib:HeapMonitorTest 
MyPackage.HeapMonitorThreadTest
   */

  import java.util.List;

cheers,
Per

On 12/13/2018 05:44 AM, JC Beyler wrote:
> Hi all,
> 
> When working on another webrev, I saw this problem:
> 
> Webrev: http://cr.openjdk.java.net/~jcbeyler/8215329/webrev.00/
> Bug: https://bugs.openjdk.java.net/browse/JDK-8215329
> 
> (Basically, from what I understood from an email from Per Liden:
>     - @requires !vm.gc.Z -> ZGC is built in the JDK
>     - @requires vm.gc != "Z" -> ZGC is being used for the runtime
> )
> 
> Thanks,
> Jc