8258483: [TESTBUG] gtest CollectorPolicy.young_scaled_initial_ergo_vm fails if heap is too small

Reviewed-by: sgehwolf
Backport-of: d08b5bd9f5f740d75c1acfbd644ce1c822e03833

Author: GoeLin

test/hotspot/gtest/gc/shared/test_collectorPolicy.cpp

@@ -78,7 +78,7 @@ class TestGenCollectorPolicy {
       FLAG_SET_ERGO(size_t, InitialHeapSize, 100 * M);
       FLAG_SET_ERGO(size_t, OldSize, 4 * M);
       FLAG_SET_ERGO(size_t, NewSize, 1 * M);
-      FLAG_SET_ERGO(size_t, MaxNewSize, 80 * M);
+      FLAG_SET_ERGO(size_t, MaxNewSize, 40 * M);
       Arguments::set_min_heap_size(40 * M);
 
       ASSERT_NO_FATAL_FAILURE(setter1->execute());
@@ -227,10 +227,16 @@ TEST_VM(CollectorPolicy, young_min_ergo) {
   TestGenCollectorPolicy::TestWrapper::test(&setter, &checker);
 }
 
+// Tests require at least 128M of MaxHeap
+// otherwise ergonomic is different and generation sizes might be changed.
+
 // If NewSize has been ergonomically set, the collector policy
 // should use it for min but calculate the initial young size
 // using NewRatio.
 TEST_VM(CollectorPolicy, young_scaled_initial_ergo) {
+  if (MaxHeapSize < 128 * M) {
+      return;
+  }
   TestGenCollectorPolicy::SetNewSizeErgo setter(20 * M);
   TestGenCollectorPolicy::CheckScaledYoungInitial checker;
 
@@ -243,6 +249,9 @@ TEST_VM(CollectorPolicy, young_scaled_initial_ergo) {
 // the rest of the VM lifetime. This is an irreversible change and
 // could impact other tests so we use TEST_OTHER_VM
 TEST_OTHER_VM(CollectorPolicy, young_cmd) {
+  if (MaxHeapSize < 128 * M) {
+    return;
+  }
   // If NewSize is set on the command line, it should be used
   // for both min and initial young size if less than min heap.
   TestGenCollectorPolicy::SetNewSizeCmd setter(20 * M);
@@ -255,8 +264,8 @@ TEST_OTHER_VM(CollectorPolicy, young_cmd) {
 
   // If NewSize is set on command line, but is larger than the min
   // heap size, it should only be used for initial young size.
-  TestGenCollectorPolicy::SetNewSizeCmd setter_large(80 * M);
-  TestGenCollectorPolicy::CheckYoungInitial checker_large(80 * M);
+  TestGenCollectorPolicy::SetNewSizeCmd setter_large(40 * M);
+  TestGenCollectorPolicy::CheckYoungInitial checker_large(40 * M);
   TestGenCollectorPolicy::TestWrapper::test(&setter_large, &checker_large);
 }