Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(783)

Unified Diff: runtime/vm/pages.cc

Issue 27802002: Disconnects code objects from infrequently used unoptimized functions. (Closed) Base URL: http://dart.googlecode.com/svn/branches/bleeding_edge/dart/
Patch Set: Created 7 years, 2 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
Index: runtime/vm/pages.cc
===================================================================
--- runtime/vm/pages.cc (revision 28803)
+++ runtime/vm/pages.cc (working copy)
@@ -23,6 +23,12 @@
"Print free list statistics before a GC");
DEFINE_FLAG(bool, print_free_list_after_gc, false,
"Print free list statistics after a GC");
+DEFINE_FLAG(bool, collect_code, true,
+ "Attempt to GC infrequently used code.");
+DEFINE_FLAG(int, code_collection_interval, 30000000,
+ "Time between attempts to collect unused code.");
+DEFINE_FLAG(bool, log_code_drop, false,
+ "Emit a log message when pointers to unused code are dropped.");
HeapPage* HeapPage::Initialize(VirtualMemory* memory, PageType type) {
ASSERT(memory->size() > VirtualMemory::PageSize());
@@ -378,11 +384,66 @@
}
+
+class CodeDropperVisitor : public ObjectVisitor {
+ public:
+ explicit CodeDropperVisitor(Isolate* isolate) : ObjectVisitor(isolate) { }
+
+ virtual void VisitObject(RawObject* obj);
+
+ private:
+ DISALLOW_COPY_AND_ASSIGN(CodeDropperVisitor);
+};
+
+
+void CodeDropperVisitor::VisitObject(RawObject* raw_obj) {
hausner 2013/10/18 17:46:17 You should also check whether there are breakpoint
zra 2013/10/22 16:13:24 Added !fn.HasBreakpoint() to the conditions for de
+ Isolate* isolate = Isolate::Current();
+ HANDLESCOPE(isolate);
+ const Object& obj = Object::Handle(raw_obj);
+ if (obj.GetClassId() == kFunctionCid) {
+ const Function& fn = Function::Cast(obj);
+ if ((fn.CurrentCode() == fn.unoptimized_code()) &&
+ (fn.usage_counter() > 0)) {
srdjan 2013/10/18 18:04:32 Use !fn.HasOptimizedCode()
zra 2013/10/22 16:13:24 Done.
+ fn.set_usage_counter(fn.usage_counter() / 2);
+ if (fn.usage_counter() == 0) {
+ if (FLAG_log_code_drop) {
+ const String& name = String::Handle(fn.name());
+ OS::Print("Dropping code for function %s\n", name.ToCString());
+ }
+ fn.DetachCode();
+ fn.set_unoptimized_code(Code::Handle());
+ }
+ }
+ }
+}
+
+
+void PageSpace::TryDroppingCode() {
+ // Try to collect code if enough time has passed since the last attempt.
+ const int64_t start = OS::GetCurrentTimeMicros();
+ const int64_t last_code_collection =
+ page_space_controller_.last_code_collection();
+ if ((start - last_code_collection) > FLAG_code_collection_interval) {
+ if (FLAG_log_code_drop) {
+ OS::Print("Trying to drop code.\n");
+ }
+ Isolate* isolate = Isolate::Current();
+ CodeDropperVisitor code_dropper(isolate);
+ heap_->IterateObjects(&code_dropper);
+ page_space_controller_.set_last_code_collection(start);
+ }
+}
+
+
void PageSpace::MarkSweep(bool invoke_api_callbacks) {
// MarkSweep is not reentrant. Make sure that is the case.
ASSERT(!sweeping_);
sweeping_ = true;
Isolate* isolate = Isolate::Current();
+ if (FLAG_collect_code) {
+ TryDroppingCode();
+ }
+
NoHandleScope no_handles(isolate);
if (FLAG_print_free_list_before_gc) {
@@ -398,7 +459,7 @@
OS::PrintErr(" done.\n");
}
- int64_t start = OS::GetCurrentTimeMicros();
+ const int64_t start = OS::GetCurrentTimeMicros();
// Mark all reachable old-gen objects.
GCMarker marker(heap_);
@@ -490,7 +551,8 @@
heap_growth_ratio_(heap_growth_ratio),
desired_utilization_((100.0 - heap_growth_ratio) / 100.0),
heap_growth_rate_(heap_growth_rate),
- garbage_collection_time_ratio_(garbage_collection_time_ratio) {
+ garbage_collection_time_ratio_(garbage_collection_time_ratio),
+ last_code_collection_(OS::GetCurrentTimeMicros()) {
}

Powered by Google App Engine
This is Rietveld 408576698