Fix the thresholds so that the heap does not grow uncontrollably. This fixes

src/heap.h

Index: src/heap.h
===================================================================
--- src/heap.h	(revision 8902)
+++ src/heap.h	(working copy)
@@ -1209,9 +1209,28 @@
            (PromotedSpaceSize() + PromotedExternalMemorySize());
   }
 
+  static const intptr_t kMinimumPromotionLimit =
+      2 * (Page::kPageSize > MB ? Page::kPageSize : MB);
+  static const intptr_t kMinimumAllocationLimit =
+      8 * (Page::kPageSize > MB ? Page::kPageSize : MB);
+  static inline intptr_t PromotionFactor(intptr_t size) {

[Vyacheslav Egorov (Chromium), 2011/08/11 15:11:34]

More comments about this magical functions would be appreciated.

[Erik Corry, 2011/08/11 16:09:08]

This function does not exist any more.

+    return size + size / 3;
+  }
+  static inline intptr_t AllocationFactor(intptr_t size) {
+    return size + size / 2;
+  }
+
   inline void LowerOldGenLimits(intptr_t bytes) {
-    old_gen_promotion_limit_ -= bytes;
-    old_gen_allocation_limit_ -= bytes;
+    old_gen_promotion_limit_ =
+        Max(old_gen_promotion_limit_ -
+                PromotionFactor(bytes) * old_gen_limit_factor_,

[Vyacheslav Egorov (Chromium), 2011/08/11 15:11:34]

multiplying factor by factor. confusing. more comments please.

old_gen_limit_factor_ is confusing name. 

[Erik Corry, 2011/08/11 16:09:08]

I was unable to find a better name, but I clarified the places it is used.

+            (kMinimumAllocationLimit + new_space_.Capacity()) *
+                old_gen_limit_factor_);
+    old_gen_allocation_limit_ =
+        Max(old_gen_allocation_limit_ -
+                AllocationFactor(bytes) * old_gen_limit_factor_,
+            (kMinimumAllocationLimit + new_space_.Capacity()) *
+                old_gen_limit_factor_);
   }
 
   // Can be called when the embedding application is idle.
@@ -1458,6 +1477,10 @@
   // every allocation in large object space.
   intptr_t old_gen_allocation_limit_;
 
+  // Sometimes the heuristics dictate that those limits are increased.  This
+  // variable records that fact.
+  int old_gen_limit_factor_;
+
   // Limit on the amount of externally allocated memory allowed
   // between global GCs. If reached a global GC is forced.
   intptr_t external_allocation_limit_;