Reduce the test heap size for concurrent immix (#330)

The heap size for concurrent immix was set to 7x, as initially it was
non-moving. Later we allowed moving for the full pause in concurrent
Immix. This PR reduces the heap size for our concurrent immix tests.

Author: qinsoon

.github/configs/large-heap.yml

@@ -10,6 +10,7 @@ configs:
   - "jdk11-master|ms|s|fail_on_oom|tph|preserve|mmtk_gc-MarkSweep"
   - "jdk11-master|ms|s|fail_on_oom|tph|preserve|mmtk_gc-MarkCompact"
   - "jdk11-master|ms|s|fail_on_oom|tph|preserve|mmtk_gc-Compressor"
+  - "jdk11-master|ms|s|fail_on_oom|tph|preserve|mmtk_gc-ConcurrentImmix"
 
 # This will be expanded in CI when we run with the config. Keep a new line at the end.
 benchmarks:

.github/configs/normal-heap.yml

@@ -10,8 +10,9 @@ jobs:
       config-file: "normal-heap.yml"
       heap-factor: "2.5"
 
-  large-heap:
-    uses: ./.github/workflows/run-dacapo-chopin-inner.yml
-    with:
-      config-file: "large-heap.yml"
-      heap-factor: "7"
+  # In case that we need to run some plans with a larger heap, we can use a different config file.
+  # large-heap:
+  #   uses: ./.github/workflows/run-dacapo-chopin-inner.yml
+  #   with:
+  #     config-file: "large-heap.yml"
+  #     heap-factor: "7"