change use_pinned_memory to true for cpu

paddle/memory/detail/system_allocator.cc

@@ -27,7 +27,7 @@ limitations under the License. */
 // between host and device.  Allocates too much would reduce the amount
 // of memory available to the system for paging.  So, by default, we
 // should set false to use_pinned_memory.
-DEFINE_bool(use_pinned_memory, false, "If set, allocate cpu pinned memory.");
+DEFINE_bool(use_pinned_memory, true, "If set, allocate cpu pinned memory.");
 
 namespace paddle {
 namespace memory {

paddle/memory/memory.cc

@@ -63,7 +63,7 @@ size_t Used<platform::CPUPlace>(platform::CPUPlace place) {
 BuddyAllocator* GetGPUBuddyAllocator(int gpu_id) {
   using BuddyAllocVec = std::vector<BuddyAllocator*>;
   static std::unique_ptr<BuddyAllocVec, void (*)(BuddyAllocVec * p)> as{
-      new std::vector<BuddyAllocator*>, [](BuddyAllocVec* p) {
+      new BuddyAllocVec, [](BuddyAllocVec* p) {
         std::for_each(p->begin(), p->end(),
                       [](BuddyAllocator* p) { delete p; });
       }};