RFR: JDK-8180450: secondary_super_cache does not scale well [v5]

[Andrew Haley]

On Fri, 22 Mar 2024 18:42:23 GMT, Andrew Haley <aph at openjdk.org> wrote:

> @theRealAph I applied your patch and ran SA tests. I did not see the failures you mentioned to me. Is there anything else special I need to do?

Yes. If you uncomment at one place, that will cause some SA failures:


index 673be99f3f2..a9be5eaaec3 100644
--- a/src/hotspot/share/classfile/classFileParser.cpp
+++ b/src/hotspot/share/classfile/classFileParser.cpp
@@ -5997,10 +5997,10 @@ void ClassFileParser::post_process_parsed_stream(const ClassFileStream* const st
   // This would be very convenient, and it would allow us to save the
   // secondary supers in hashed order, but some SA tests know the
   // order of secondary supers.
-  // if (HashSecondarySupers) {
-  //   // Put the transitive interfaces into hash order
-  //   Klass::hash_secondary_supers(_transitive_interfaces, /*rewrite*/true);
-  // }
+  if (HashSecondarySupers) {
+    // Put the transitive interfaces into hash order
+    Klass::hash_secondary_supers(_transitive_interfaces, /*rewrite*/true);
+  }
 
   // sort methods
   _method_ordering = sort_methods(_methods);



[runtime/LoaderConstraints/itableICCE/Test.java]
[serviceability/dcmd/vm/ClassHierarchyTest.java]: Test of diagnostic command VM.class_hierarchy

The only difference is the order of the interfaces. I think the tests may be invalid, but I'm not sure.

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PR Comment: https://git.openjdk.org/jdk/pull/18309#issuecomment-2020242215