src/share/vm/runtime/arguments.cpp

*** 1520,1529 ****
--- 1520,1543 ----
      if (FLAG_IS_DEFAULT(UseCompressedClassPointers)) {
        FLAG_SET_ERGO(bool, UseCompressedClassPointers, true);
      }
      // Check the CompressedClassSpaceSize to make sure we use compressed klass ptrs.
      if (UseCompressedClassPointers) {
+       size_t min_metaspace_sz = InitialBootClassLoaderMetaspaceSize +
+                                (64 * K * HeapWordSize); // MediumChunk in bytes.
+ 
+       if ((min_metaspace_sz + CompressedClassSpaceSize) >  MaxMetaspaceSize) {
+         if (min_metaspace_sz >= MaxMetaspaceSize) {
+           vm_exit_during_initialization(
+                    "InitialBootClassLoaderMetaspaceSize should be " 
+                                                 "less than MaxMetaspaceSize.");
+         } else {
+           FLAG_SET_ERGO(size_t, CompressedClassSpaceSize,
+                                         MaxMetaspaceSize - min_metaspace_sz);
+         }
+       }
+ 
        if (CompressedClassSpaceSize > KlassEncodingMetaspaceMax) {
          warning("CompressedClassSpaceSize is too large for UseCompressedClassPointers");
          FLAG_SET_DEFAULT(UseCompressedClassPointers, false);
        }
      }