Release evacuation candidates after parallel sweeper threads completed.

src/mark-compact.cc

Index: src/mark-compact.cc
diff --git a/src/mark-compact.cc b/src/mark-compact.cc
index 5f22565fb9268a21bb5e548c9a74c8ed77067d82..a3dda72af2b7241cb700870869def9d215c9d36a 100644
--- a/src/mark-compact.cc
+++ b/src/mark-compact.cc
@@ -541,6 +541,7 @@ void MarkCompactCollector::WaitUntilSweepingCompleted() {
       heap()->isolate()->sweeper_threads()[i]->WaitForSweeperThread();
     }
     sweeping_pending_ = false;
+    ReleaseEvacuationCandidates();
     StealMemoryFromSweeperThreads(heap()->paged_space(OLD_DATA_SPACE));
     StealMemoryFromSweeperThreads(heap()->paged_space(OLD_POINTER_SPACE));
     heap()->FreeQueuedChunks();
@@ -3280,6 +3281,11 @@ void MarkCompactCollector::EvacuateNewSpaceAndCandidates() {
 
   slots_buffer_allocator_.DeallocateChain(&migration_slots_buffer_);
   ASSERT(migration_slots_buffer_ == NULL);
+}
+
+
+void MarkCompactCollector::ReleaseEvacuationCandidates() {
+  int npages = evacuation_candidates_.length();
   for (int i = 0; i < npages; i++) {
     Page* p = evacuation_candidates_[i];
     if (!p->IsEvacuationCandidate()) continue;
@@ -3877,6 +3883,10 @@ void MarkCompactCollector::SweepSpaces() {
 
   // Deallocate unmarked objects and clear marked bits for marked objects.
   heap_->lo_space()->FreeUnmarkedObjects();
+
+  if (!AreSweeperThreadsActivated()) {

[Michael Starzinger, 2013/02/20 18:20:07]

... but called down here at this call-site. Also I would change the if-cascade
to use the same predicates:

if (how_to_sweep == PARALLEL_CONSERVATIVE) {
  if (FLAG_parallel_sweeping && !FLAG_concurrent_sweeping) {
    FinalizeSweeping();
  }
}

[Hannes Payer (out of office), 2013/02/21 12:05:17]

The right condition is "if (!FLAG_concurrent_sweeping)" since it has to be
finalized in parallel and sequential mode.

On 2013/02/20 18:20:07, Michael Starzinger wrote:

+    ReleaseEvacuationCandidates();
+  }
 }