Lower heap size limits on systems that are short of virtual memory.

src/heap.cc

Index: src/heap.cc
===================================================================
--- src/heap.cc	(revision 8132)
+++ src/heap.cc	(working copy)
@@ -152,6 +152,15 @@
   max_semispace_size_ = reserved_semispace_size_ = V8_MAX_SEMISPACE_SIZE;
 #endif
 
+  intptr_t max_virtual = OS::MaxVirtualMemory();
+
+  if (max_virtual > 0) {
+    if (code_range_size_ > 0) {

[Kasper Lund, 2011/06/01 08:23:49]

It would be nice with a comment here that explains how the max virtual memory is
carved up. It's not completely clear why you use 1/4 on code and 1/2 on old gen
(what do you use the last 1/4 on)? If code_range_size_ == 0 why don't you want
to use the same fraction of max_virtual?

+      code_range_size_ = Min(code_range_size_, max_virtual >> 2);
+    }
+    max_old_generation_size_ = Min(max_old_generation_size_, max_virtual >> 1);
+  }
+
   memset(roots_, 0, sizeof(roots_[0]) * kRootListLength);
   global_contexts_list_ = NULL;
   mark_compact_collector_.heap_ = this;