Reduce boot-up memory use of V8.

src/heap.cc

 // Copyright 2012 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 564 matching lines @@
     int map_space_size,
     int cell_space_size,
     int large_object_size) {
   NewSpace* new_space = Heap::new_space();
   PagedSpace* old_pointer_space = Heap::old_pointer_space();
   PagedSpace* old_data_space = Heap::old_data_space();
   PagedSpace* code_space = Heap::code_space();
   PagedSpace* map_space = Heap::map_space();
   PagedSpace* cell_space = Heap::cell_space();
   LargeObjectSpace* lo_space = Heap::lo_space();
+  bool one_old_space_gc_has_been_performed = false;
   bool gc_performed = true;
-  int counter = 0;
-  static const int kThreshold = 20;
-  while (gc_performed && counter++ < kThreshold) {
+  bool old_space_gc_performed;
+  while (gc_performed) {

[Vyacheslav Egorov (Chromium), 2012/01/26 16:12:05]

it seems to me that this loop can go on forever. can you prove that we are not
going to loop here forever doing GC if OS refuses us new pages and we at the
boundary of soft/hard limit?

+    old_space_gc_performed = false;
     gc_performed = false;
     if (!new_space->ReserveSpace(new_space_size)) {
       Heap::CollectGarbage(NEW_SPACE);
       gc_performed = true;
     }
     if (!old_pointer_space->ReserveSpace(pointer_space_size)) {
       Heap::CollectGarbage(OLD_POINTER_SPACE);
       gc_performed = true;
+      old_space_gc_performed = true;
     }
     if (!(old_data_space->ReserveSpace(data_space_size))) {
       Heap::CollectGarbage(OLD_DATA_SPACE);
       gc_performed = true;
+      old_space_gc_performed = true;
     }
     if (!(code_space->ReserveSpace(code_space_size))) {
       Heap::CollectGarbage(CODE_SPACE);
       gc_performed = true;
+      old_space_gc_performed = true;
     }
     if (!(map_space->ReserveSpace(map_space_size))) {
       Heap::CollectGarbage(MAP_SPACE);
       gc_performed = true;
+      old_space_gc_performed = true;
     }
     if (!(cell_space->ReserveSpace(cell_space_size))) {
       Heap::CollectGarbage(CELL_SPACE);
       gc_performed = true;
+      old_space_gc_performed = true;
     }
     // We add a slack-factor of 2 in order to have space for a series of
     // large-object allocations that are only just larger than the page size.
     large_object_size *= 2;
     // The ReserveSpace method on the large object space checks how much
     // we can expand the old generation.  This includes expansion caused by
     // allocation in the other spaces.
     large_object_size += cell_space_size + map_space_size + code_space_size +
         data_space_size + pointer_space_size;
-    if (!(lo_space->ReserveSpace(large_object_size))) {
+
+    // If we already did one GC in order to make space in old space, there is
+    // no sense in doing another one.  We will attempt to force through the
+    // large object space allocation, which comes directly from the OS,
+    // regardless of any soft limit.
+    if (!one_old_space_gc_has_been_performed &&
+        !(lo_space->ReserveSpace(large_object_size))) {
       Heap::CollectGarbage(LO_SPACE);
       gc_performed = true;
     }
-  }
-
-  if (gc_performed) {
-    // Failed to reserve the space after several attempts.
-    V8::FatalProcessOutOfMemory("Heap::ReserveSpace");
+    if (old_space_gc_performed) one_old_space_gc_has_been_performed = true;
   }
 }
 
 
 void Heap::EnsureFromSpaceIsCommitted() {
   if (new_space_.CommitFromSpaceIfNeeded()) return;
 
   // Committing memory to from space failed.
   // Try shrinking and try again.
   Shrink();
@@ skipping 6094 matching lines @@
   isolate_->heap()->store_buffer()->Compact();
   isolate_->heap()->store_buffer()->Filter(MemoryChunk::ABOUT_TO_BE_FREED);
   for (chunk = chunks_queued_for_free_; chunk != NULL; chunk = next) {
     next = chunk->next_chunk();
     isolate_->memory_allocator()->Free(chunk);
   }
   chunks_queued_for_free_ = NULL;
 }
 
 } }  // namespace v8::internal