indexing multithreaded by default

platform/platform-impl/src/com/intellij/openapi/project/CacheUpdateRunner.java

@@ -134,6 +134,9 @@ class CacheUpdateRunner {
     final boolean[] isFinished = new boolean[1];
     try {
       int threadsCount = Registry.intValue("caches.indexerThreadsCount");
+      if (threadsCount == -1) {
+        threadsCount = Math.min(Runtime.getRuntime().availableProcessors(), 2);
+      }
       if (threadsCount == 1) {
         Runnable process = new MyRunnable(innerIndicator, queue, isFinished, progressUpdater, processInReadAction, application);
         ProgressManager.getInstance().runProcess(process, innerIndicator);

platform/platform-resources-en/src/misc/registry.properties

@@ -99,4 +99,4 @@ jar.build=false
 
 keymap.show.alias.actions=false
 frameworks.download.libraries.server.url=http://pluginsrepo-test:8080
-caches.indexerThreadsCount=1
+caches.indexerThreadsCount=-1