Enable large object space for zygote.
We now enable the large object space before the zygote fork.
This reduces the size of the zygote and removes the need for
excessive explicit GCs during phone booting.
Changed the card set mod union table to support forgetting cards.
If a card has no non null references which are in another space
then it is removed from the set.
Added logging of the zygote size when you do a SIGQUIT.
Dalvik PSS is the same or slightly lower (1-3%).
Zygote space size:
Before: 15MB
After: 8MB (+ some large objects).
TODO: Combine remembered sets and mod union tables into a single
interface.
Bug: 16398684
Change-Id: Ie48cdf35004a0a37eedb1ccc1bf214b1fa9e0cca
diff --git a/runtime/gc/accounting/mod_union_table.cc b/runtime/gc/accounting/mod_union_table.cc
index 2686af0..3acf80d 100644
--- a/runtime/gc/accounting/mod_union_table.cc
+++ b/runtime/gc/accounting/mod_union_table.cc
@@ -72,9 +72,11 @@
class ModUnionUpdateObjectReferencesVisitor {
public:
- ModUnionUpdateObjectReferencesVisitor(MarkHeapReferenceCallback* callback, void* arg)
- : callback_(callback),
- arg_(arg) {
+ ModUnionUpdateObjectReferencesVisitor(MarkHeapReferenceCallback* callback, void* arg,
+ space::ContinuousSpace* from_space,
+ bool* contains_reference_to_other_space)
+ : callback_(callback), arg_(arg), from_space_(from_space),
+ contains_reference_to_other_space_(contains_reference_to_other_space) {
}
// Extra parameters are required since we use this same visitor signature for checking objects.
@@ -82,7 +84,9 @@
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
// Only add the reference if it is non null and fits our criteria.
mirror::HeapReference<Object>* obj_ptr = obj->GetFieldObjectReferenceAddr(offset);
- if (obj_ptr->AsMirrorPtr() != nullptr) {
+ mirror::Object* ref = obj_ptr->AsMirrorPtr();
+ if (ref != nullptr && !from_space_->HasAddress(ref)) {
+ *contains_reference_to_other_space_ = true;
callback_(obj_ptr, arg_);
}
}
@@ -90,24 +94,36 @@
private:
MarkHeapReferenceCallback* const callback_;
void* arg_;
+ // Space which we are scanning
+ space::ContinuousSpace* const from_space_;
+ // Set if we have any references to another space.
+ bool* const contains_reference_to_other_space_;
};
class ModUnionScanImageRootVisitor {
public:
- ModUnionScanImageRootVisitor(MarkHeapReferenceCallback* callback, void* arg)
- : callback_(callback), arg_(arg) {}
+ ModUnionScanImageRootVisitor(MarkHeapReferenceCallback* callback, void* arg,
+ space::ContinuousSpace* from_space,
+ bool* contains_reference_to_other_space)
+ : callback_(callback), arg_(arg), from_space_(from_space),
+ contains_reference_to_other_space_(contains_reference_to_other_space) {}
void operator()(Object* root) const
EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
DCHECK(root != NULL);
- ModUnionUpdateObjectReferencesVisitor ref_visitor(callback_, arg_);
+ ModUnionUpdateObjectReferencesVisitor ref_visitor(callback_, arg_, from_space_,
+ contains_reference_to_other_space_);
root->VisitReferences<kMovingClasses>(ref_visitor, VoidFunctor());
}
private:
MarkHeapReferenceCallback* const callback_;
void* const arg_;
+ // Space which we are scanning
+ space::ContinuousSpace* const from_space_;
+ // Set if we have any references to another space.
+ bool* const contains_reference_to_other_space_;
};
void ModUnionTableReferenceCache::ClearCards() {
@@ -313,12 +329,20 @@
void ModUnionTableCardCache::UpdateAndMarkReferences(MarkHeapReferenceCallback* callback,
void* arg) {
CardTable* card_table = heap_->GetCardTable();
- ModUnionScanImageRootVisitor scan_visitor(callback, arg);
ContinuousSpaceBitmap* bitmap = space_->GetLiveBitmap();
- for (const byte* card_addr : cleared_cards_) {
- uintptr_t start = reinterpret_cast<uintptr_t>(card_table->AddrFromCard(card_addr));
+ bool reference_to_other_space = false;
+ ModUnionScanImageRootVisitor scan_visitor(callback, arg, space_, &reference_to_other_space);
+ for (auto it = cleared_cards_.begin(), end = cleared_cards_.end(); it != end; ) {
+ uintptr_t start = reinterpret_cast<uintptr_t>(card_table->AddrFromCard(*it));
DCHECK(space_->HasAddress(reinterpret_cast<Object*>(start)));
+ reference_to_other_space = false;
bitmap->VisitMarkedRange(start, start + CardTable::kCardSize, scan_visitor);
+ if (!reference_to_other_space) {
+ // No non null reference to another space, remove the card.
+ it = cleared_cards_.erase(it);
+ } else {
+ ++it;
+ }
}
}
@@ -333,6 +357,17 @@
os << "]";
}
+void ModUnionTableCardCache::SetCards() {
+ CardTable* card_table = heap_->GetCardTable();
+ for (byte* addr = space_->Begin(); addr < AlignUp(space_->End(), CardTable::kCardSize);
+ addr += CardTable::kCardSize) {
+ cleared_cards_.insert(card_table->CardFromAddr(addr));
+ }
+}
+
+void ModUnionTableReferenceCache::SetCards() {
+}
+
} // namespace accounting
} // namespace gc
} // namespace art