Be more willing to expand old space when evacuating new space at the end of

src/spaces.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2124 matching lines @@
 
     allocation_info_.top = NULL;
     allocation_info_.limit = NULL;
   }
 }
 
 
 HeapObject* PagedSpace::SlowAllocateRaw(int size_in_bytes) {
   // Allocation in this space has failed.
 
+  // If there are unswept pages advance lazy sweeper then sweep one page before
+  // allocating a new page.
+  if (first_unswept_page_->is_valid()) {
+    AdvanceSweeper(size_in_bytes);
+
+    // Retry the free list allocation.
+    HeapObject* object = free_list_.Allocate(size_in_bytes);
+    if (object != NULL) return object;
+  }
+
   // Free list allocation failed and there is no next page.  Fail if we have
   // hit the old generation size limit that should cause a garbage
   // collection.
   if (!heap()->always_allocate() &&
       heap()->OldGenerationAllocationLimitReached()) {
     return NULL;
   }
 
-  // If there are unswept pages advance lazy sweeper.
-  if (first_unswept_page_->is_valid()) {
-    AdvanceSweeper(size_in_bytes);
-
-    // Retry the free list allocation.
-    HeapObject* object = free_list_.Allocate(size_in_bytes);
-    if (object != NULL) return object;
-
-    if (!IsSweepingComplete()) {
-      AdvanceSweeper(kMaxInt);
-
-      // Retry the free list allocation.
-      object = free_list_.Allocate(size_in_bytes);
-      if (object != NULL) return object;
-    }
-  }
-
   // Try to expand the space and allocate in the new next page.
   if (Expand()) {
     return free_list_.Allocate(size_in_bytes);
   }
 
+  // Last ditch, sweep all the remaining pages to try to find space.  This may
+  // cause a pause.
+  if (!IsSweepingComplete()) {
+    AdvanceSweeper(kMaxInt);
+
+    // Retry the free list allocation.
+    HeapObject* object = free_list_.Allocate(size_in_bytes);
+    if (object != NULL) return object;
+  }
+
   // Finally, fail.
   return NULL;
 }
 
 
 #ifdef DEBUG
 void PagedSpace::ReportCodeStatistics() {
   Isolate* isolate = Isolate::Current();
   CommentStatistic* comments_statistics =
       isolate->paged_space_comments_statistics();
@@ skipping 465 matching lines @@
     object->ShortPrint();
     PrintF("\n");
   }
   printf(" --------------------------------------\n");
   printf(" Marked: %x, LiveCount: %x\n", mark_size, LiveBytes());
 }
 
 #endif  // DEBUG
 
 } }  // namespace v8::internal