Temporarily increase heap min and max free

Make sure that GC doesn't run too often for TLAB ergonomics. Added a
regression test.

Bug: 34576638

Test: test-art-host

Change-Id: Ie07c7c470aaca044fea20b21cbe6bfe8667d082f
diff --git a/runtime/gc/heap.cc b/runtime/gc/heap.cc
index 268cca0..7044979 100644
--- a/runtime/gc/heap.cc
+++ b/runtime/gc/heap.cc
@@ -3543,8 +3543,11 @@
   collector::GcType gc_type = collector_ran->GetGcType();
   const double multiplier = HeapGrowthMultiplier();  // Use the multiplier to grow more for
   // foreground.
-  const uint64_t adjusted_min_free = static_cast<uint64_t>(min_free_ * multiplier);
-  const uint64_t adjusted_max_free = static_cast<uint64_t>(max_free_ * multiplier);
+  // Ensure at least 2.5 MB to temporarily fix excessive GC caused by TLAB ergonomics.
+  const uint64_t adjusted_min_free = std::max(static_cast<uint64_t>(min_free_ * multiplier),
+                                              static_cast<uint64_t>(5 * MB / 2));
+  const uint64_t adjusted_max_free = std::max(static_cast<uint64_t>(max_free_ * multiplier),
+                                              static_cast<uint64_t>(5 * MB / 2));
   if (gc_type != collector::kGcTypeSticky) {
     // Grow the heap for non sticky GC.
     ssize_t delta = bytes_allocated / GetTargetHeapUtilization() - bytes_allocated;
diff --git a/test/154-gc-loop/expected.txt b/test/154-gc-loop/expected.txt
new file mode 100644
index 0000000..6106818
--- /dev/null
+++ b/test/154-gc-loop/expected.txt
@@ -0,0 +1,2 @@
+JNI_OnLoad called
+Finalize count too large: false
diff --git a/test/154-gc-loop/heap_interface.cc b/test/154-gc-loop/heap_interface.cc
new file mode 100644
index 0000000..8d610a8
--- /dev/null
+++ b/test/154-gc-loop/heap_interface.cc
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "gc/heap.h"
+#include "runtime.h"
+
+namespace art {
+namespace {
+
+extern "C" JNIEXPORT void JNICALL Java_Main_backgroundProcessState(JNIEnv*, jclass) {
+  Runtime::Current()->UpdateProcessState(kProcessStateJankImperceptible);
+}
+
+}  // namespace
+}  // namespace art
diff --git a/test/154-gc-loop/info.txt b/test/154-gc-loop/info.txt
new file mode 100644
index 0000000..f599db1
--- /dev/null
+++ b/test/154-gc-loop/info.txt
@@ -0,0 +1 @@
+Test that GC doesn't happen too often for a few small allocations.
diff --git a/test/154-gc-loop/src/Main.java b/test/154-gc-loop/src/Main.java
new file mode 100644
index 0000000..3a256c1
--- /dev/null
+++ b/test/154-gc-loop/src/Main.java
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import java.lang.ref.WeakReference;
+
+public class Main {
+  static final class GcWatcher {
+    protected void finalize() throws Throwable {
+        watcher = new WeakReference<GcWatcher>(new GcWatcher());
+        ++finalizeCounter;
+    }
+  }
+  static WeakReference<GcWatcher> watcher = new WeakReference<GcWatcher>(new GcWatcher());
+  static Object o = new Object();
+  static int finalizeCounter = 0;
+
+  public static void main(String[] args) {
+    System.loadLibrary(args[0]);
+    backgroundProcessState();
+    try {
+        Runtime.getRuntime().gc();
+        for (int i = 0; i < 10; ++i) {
+            o = new Object();
+            Thread.sleep(1000);
+        }
+    } catch (Exception e) {}
+    System.out.println("Finalize count too large: " +
+            ((finalizeCounter >= 10) ? Integer.toString(finalizeCounter) : "false"));
+  }
+
+  private static native void backgroundProcessState();
+}
diff --git a/test/Android.bp b/test/Android.bp
index 89e4092..7143b91 100644
--- a/test/Android.bp
+++ b/test/Android.bp
@@ -317,6 +317,7 @@
         "141-class-unload/jni_unload.cc",
         "148-multithread-gc-annotations/gc_coverage.cc",
         "149-suspend-all-stress/suspend_all.cc",
+        "154-gc-loop/heap_interface.cc",
         "454-get-vreg/get_vreg_jni.cc",
         "457-regs/regs_jni.cc",
         "461-get-reference-vreg/get_reference_vreg_jni.cc",