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

src/spaces.cc

Index: src/spaces.cc
diff --git a/src/spaces.cc b/src/spaces.cc
index 583b2ca5124982cda6302c4b6b62213b34c2752a..d03707ec8adcc0ce1d91e1a8e144f24faa09f47c 100644
--- a/src/spaces.cc
+++ b/src/spaces.cc
@@ -2390,10 +2390,14 @@ void PagedSpace::EvictEvacuationCandidatesFromFreeLists() {
 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);