Reviewers: Vyacheslav Egorov,
Description:
Make heap size estimation more accurate.
This improves the heap size estimation by not counting lazy swept pages
as completely allocated but use their live bytes counter instead.
[email protected]
BUG=v8:1892
TEST=cctest/test-heap/TestSizeOfObjects
Please review this at http://codereview.chromium.org/9173001/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files:
M src/spaces.h
M src/spaces.cc
M test/cctest/test-heap.cc
Index: src/spaces.cc
diff --git a/src/spaces.cc b/src/spaces.cc
index
ebd3e6519208d9103a1b9d5e5bd975442d14c7fb..1bcea22b8e1850116c44ac91f384cad426888898
100644
--- a/src/spaces.cc
+++ b/src/spaces.cc
@@ -749,6 +749,20 @@ int PagedSpace::CountTotalPages() {
}
+intptr_t PagedSpace::SizeOfObjectsSlow() {
+ PageIterator it(this);
+ intptr_t size_of_objects = accounting_stats_.Size();
+ while (it.has_next()) {
+ Page* p = it.next();
+ if (!p->WasSwept()) {
+ size_of_objects -= Page::kObjectAreaSize;
+ size_of_objects += p->LiveBytes();
+ }
+ }
+ return size_of_objects - (limit() - top());
+}
+
+
void PagedSpace::ReleasePage(Page* page) {
ASSERT(page->LiveBytes() == 0);
Index: src/spaces.h
diff --git a/src/spaces.h b/src/spaces.h
index
41bfec90f142797bdc295d622505ee963c6b05c6..60432e39cf7c30a55da8131e52fba42350705b7e
100644
--- a/src/spaces.h
+++ b/src/spaces.h
@@ -1469,9 +1469,16 @@ class PagedSpace : public Space {
// linear allocation area (between top and limit) are also counted here.
virtual intptr_t Size() { return accounting_stats_.Size(); }
- // As size, but the bytes in the current linear allocation area are not
- // included.
- virtual intptr_t SizeOfObjects() { return Size() - (limit() - top()); }
+ // As size, but the bytes in lazily swept pages are estimated and the
bytes
+ // in the current linear allocation area are not included.
+ intptr_t SizeOfObjectsSlow();
+ virtual intptr_t SizeOfObjects() {
+ if (IsSweepingComplete()) {
+ return Size() - (limit() - top());
+ } else {
+ return SizeOfObjectsSlow();
+ }
+ }
// Wasted bytes in this space. These are just the bytes that were
thrown away
// due to being too small to use for allocation. They do not include the
@@ -1479,9 +1486,7 @@ class PagedSpace : public Space {
virtual intptr_t Waste() { return accounting_stats_.Waste(); }
// Returns the allocation pointer in this space.
- Address top() {
- return allocation_info_.top;
- }
+ Address top() { return allocation_info_.top; }
Address limit() { return allocation_info_.limit; }
// Allocate the requested number of bytes in the space if possible,
return a
Index: test/cctest/test-heap.cc
diff --git a/test/cctest/test-heap.cc b/test/cctest/test-heap.cc
index
42b5789d4d02f17f520af87c6a27c148e2b59dbc..da64ba9cc5c85a2a8d61efa77e93909a5cc4f77d
100644
--- a/test/cctest/test-heap.cc
+++ b/test/cctest/test-heap.cc
@@ -1187,6 +1187,35 @@ TEST(TestInternalWeakListsTraverseWithGC) {
}
+TEST(TestSizeOfObjects) {
+ v8::V8::Initialize();
+
+ // Get initial heap size after a full GC, which should return after
+ // sweeping finished completely.
+ HEAP->CollectAllGarbage(Heap::kNoGCFlags);
+ CHECK(HEAP->old_pointer_space()->IsSweepingComplete());
+ intptr_t initial_size = HEAP->SizeOfObjects();
+
+ {
+ // Allocate objects on two different old-space pages so that lazy
+ // sweeping kicks in for subsequent GC runs.
+ AlwaysAllocateScope always_allocate;
+ intptr_t filler_size = FixedArray::SizeFor(8192);
+ for (int i = 1; i <= 100; i++) {
+ HEAP->AllocateFixedArray(8192, TENURED)->ToObjectChecked();
+ CHECK_EQ(initial_size + i * filler_size, HEAP->SizeOfObjects());
+ }
+ }
+
+ // The heap size should go back to initial size after a full GC, even
+ // though sweeping didn't finish yet (with a delta of about 512 words).
+ HEAP->CollectAllGarbage(Heap::kNoGCFlags);
+ CHECK(!HEAP->old_pointer_space()->IsSweepingComplete());
+ CHECK_LE(HEAP->SizeOfObjects(), initial_size);
+ CHECK_GT(HEAP->SizeOfObjects(), initial_size - 512 * kPointerSize);
+}
+
+
TEST(TestSizeOfObjectsVsHeapIteratorPrecision) {
InitializeVM();
HEAP->EnsureHeapIsIterable();
--
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