Remove eager sweeping for lazy swept spaces. Try to find in SlowAllocateRaw a bounded number of tim…

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 2372 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);
+  // If there are unswept pages advance lazy sweeper a bounded number of times
+  // until we find a size_in_bytes contiguous piece of memory

[Hannes Payer (out of office), 2012/11/15 13:08:46]

there are so many heuristics all over the gc...

+  const int kMaxSweepingTries = 5;
+  const int kAllocationSweepingFactor = 10;
+  int i = 0;
+
+  for (i = 0; i < kMaxSweepingTries && first_unswept_page_->is_valid(); i++) {
+    AdvanceSweeper(size_in_bytes * kAllocationSweepingFactor);
 
     // 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() &&
@@ skipping 538 matching lines @@
     object->ShortPrint();
     PrintF("\n");
   }
   printf(" --------------------------------------\n");
   printf(" Marked: %x, LiveCount: %x\n", mark_size, LiveBytes());
 }
 
 #endif  // DEBUG
 
 } }  // namespace v8::internal