Add fallback for non moving space being full.
When the non moving space becomes full, we disable moving GC and
make the main space the new non moving space.
Also added a runtime option for changing the non moving space size:
-XX:NonMovingSpaceCapacity.
Bug: 17189964
(cherry picked from commit 4c5a469683e433f126c9863cd393747d2e7c4a29)
Change-Id: If82e3c6f8a0f389e37e14a0b1e6d5126d571fd7a
diff --git a/runtime/gc/heap.cc b/runtime/gc/heap.cc
index 1e01164..898c258 100644
--- a/runtime/gc/heap.cc
+++ b/runtime/gc/heap.cc
@@ -86,7 +86,6 @@
static constexpr bool kUseFreeListSpaceForLOS = false;
// Whether or not we compact the zygote in PreZygoteFork.
static constexpr bool kCompactZygote = kMovingCollector;
-static constexpr size_t kNonMovingSpaceCapacity = 64 * MB;
// How many reserve entries are at the end of the allocation stack, these are only needed if the
// allocation stack overflows.
static constexpr size_t kAllocationStackReserveSize = 1024;
@@ -99,10 +98,11 @@
static constexpr size_t kGSSBumpPointerSpaceCapacity = 32 * MB;
Heap::Heap(size_t initial_size, size_t growth_limit, size_t min_free, size_t max_free,
- double target_utilization, double foreground_heap_growth_multiplier, size_t capacity,
- const std::string& image_file_name, const InstructionSet image_instruction_set,
- CollectorType foreground_collector_type, CollectorType background_collector_type,
- size_t parallel_gc_threads, size_t conc_gc_threads, bool low_memory_mode,
+ double target_utilization, double foreground_heap_growth_multiplier,
+ size_t capacity, size_t non_moving_space_capacity, const std::string& image_file_name,
+ const InstructionSet image_instruction_set, CollectorType foreground_collector_type,
+ CollectorType background_collector_type, size_t parallel_gc_threads,
+ size_t conc_gc_threads, bool low_memory_mode,
size_t long_pause_log_threshold, size_t long_gc_log_threshold,
bool ignore_max_footprint, bool use_tlab,
bool verify_pre_gc_heap, bool verify_pre_sweeping_heap, bool verify_post_gc_heap,
@@ -214,7 +214,7 @@
}
/*
requested_alloc_space_begin -> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
- +- nonmoving space (kNonMovingSpaceCapacity) +-
+ +- nonmoving space (non_moving_space_capacity)+-
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
+-main alloc space / bump space 1 (capacity_) +-
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
@@ -241,7 +241,7 @@
std::unique_ptr<MemMap> main_mem_map_2;
byte* request_begin = requested_alloc_space_begin;
if (request_begin != nullptr && separate_non_moving_space) {
- request_begin += kNonMovingSpaceCapacity;
+ request_begin += non_moving_space_capacity;
}
std::string error_str;
std::unique_ptr<MemMap> non_moving_space_mem_map;
@@ -250,7 +250,7 @@
// address.
non_moving_space_mem_map.reset(
MemMap::MapAnonymous("non moving space", requested_alloc_space_begin,
- kNonMovingSpaceCapacity, PROT_READ | PROT_WRITE, true, &error_str));
+ non_moving_space_capacity, PROT_READ | PROT_WRITE, true, &error_str));
CHECK(non_moving_space_mem_map != nullptr) << error_str;
}
// Attempt to create 2 mem maps at or after the requested begin.
@@ -271,7 +271,7 @@
// active rosalloc spaces.
const size_t size = non_moving_space_mem_map->Size();
non_moving_space_ = space::DlMallocSpace::CreateFromMemMap(
- non_moving_space_mem_map.release(), "zygote / non moving space", initial_size,
+ non_moving_space_mem_map.release(), "zygote / non moving space", kDefaultStartingSize,
initial_size, size, size, false);
non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity());
CHECK(non_moving_space_ != nullptr) << "Failed creating non moving space "
@@ -491,14 +491,33 @@
}
}
-void Heap::DisableCompaction() {
+void Heap::DisableMovingGc() {
if (IsMovingGc(foreground_collector_type_)) {
- foreground_collector_type_ = kCollectorTypeCMS;
+ foreground_collector_type_ = kCollectorTypeCMS;
}
if (IsMovingGc(background_collector_type_)) {
background_collector_type_ = foreground_collector_type_;
}
TransitionCollector(foreground_collector_type_);
+ ThreadList* tl = Runtime::Current()->GetThreadList();
+ Thread* self = Thread::Current();
+ ScopedThreadStateChange tsc(self, kSuspended);
+ tl->SuspendAll();
+ // Something may have caused the transition to fail.
+ if (!IsMovingGc(foreground_collector_type_) && non_moving_space_ != main_space_) {
+ CHECK(main_space_ != nullptr);
+ // The allocation stack may have non movable objects in it. We need to flush it since the GC
+ // can't only handle marking allocation stack objects of one non moving space and one main
+ // space.
+ {
+ WriterMutexLock mu(self, *Locks::heap_bitmap_lock_);
+ FlushAllocStack();
+ }
+ main_space_->DisableMovingObjects();
+ non_moving_space_ = main_space_;
+ CHECK(!non_moving_space_->CanMoveObjects());
+ }
+ tl->ResumeAll();
}
std::string Heap::SafeGetClassDescriptor(mirror::Class* klass) {
@@ -1262,41 +1281,73 @@
return nullptr;
}
ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size);
- if (ptr == nullptr && use_homogeneous_space_compaction_for_oom_) {
+ if (ptr == nullptr) {
const uint64_t current_time = NanoTime();
- if ((allocator == kAllocatorTypeRosAlloc || allocator == kAllocatorTypeDlMalloc) &&
- current_time - last_time_homogeneous_space_compaction_by_oom_ >
- min_interval_homogeneous_space_compaction_by_oom_) {
- last_time_homogeneous_space_compaction_by_oom_ = current_time;
- HomogeneousSpaceCompactResult result = PerformHomogeneousSpaceCompact();
- switch (result) {
- case HomogeneousSpaceCompactResult::kSuccess:
- // If the allocation succeeded, we delayed an oom.
- ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size);
- if (ptr != nullptr) {
- count_delayed_oom_++;
+ switch (allocator) {
+ case kAllocatorTypeRosAlloc:
+ // Fall-through.
+ case kAllocatorTypeDlMalloc: {
+ if (use_homogeneous_space_compaction_for_oom_ &&
+ current_time - last_time_homogeneous_space_compaction_by_oom_ >
+ min_interval_homogeneous_space_compaction_by_oom_) {
+ last_time_homogeneous_space_compaction_by_oom_ = current_time;
+ HomogeneousSpaceCompactResult result = PerformHomogeneousSpaceCompact();
+ switch (result) {
+ case HomogeneousSpaceCompactResult::kSuccess:
+ // If the allocation succeeded, we delayed an oom.
+ ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated,
+ usable_size);
+ if (ptr != nullptr) {
+ count_delayed_oom_++;
+ }
+ break;
+ case HomogeneousSpaceCompactResult::kErrorReject:
+ // Reject due to disabled moving GC.
+ break;
+ case HomogeneousSpaceCompactResult::kErrorVMShuttingDown:
+ // Throw OOM by default.
+ break;
+ default: {
+ LOG(FATAL) << "Unimplemented homogeneous space compaction result "
+ << static_cast<size_t>(result);
+ }
}
- break;
- case HomogeneousSpaceCompactResult::kErrorReject:
- // Reject due to disabled moving GC.
- break;
- case HomogeneousSpaceCompactResult::kErrorVMShuttingDown:
- // Throw OOM by default.
- break;
- default: {
- LOG(FATAL) << "Unimplemented homogeneous space compaction result " << static_cast<size_t>(result);
+ // Always print that we ran homogeneous space compation since this can cause jank.
+ VLOG(heap) << "Ran heap homogeneous space compaction, "
+ << " requested defragmentation "
+ << count_requested_homogeneous_space_compaction_.LoadSequentiallyConsistent()
+ << " performed defragmentation "
+ << count_performed_homogeneous_space_compaction_.LoadSequentiallyConsistent()
+ << " ignored homogeneous space compaction "
+ << count_ignored_homogeneous_space_compaction_.LoadSequentiallyConsistent()
+ << " delayed count = "
+ << count_delayed_oom_.LoadSequentiallyConsistent();
}
+ break;
}
- // Always print that we ran homogeneous space compation since this can cause jank.
- VLOG(heap) << "Ran heap homogeneous space compaction, "
- << " requested defragmentation "
- << count_requested_homogeneous_space_compaction_.LoadSequentiallyConsistent()
- << " performed defragmentation "
- << count_performed_homogeneous_space_compaction_.LoadSequentiallyConsistent()
- << " ignored homogeneous space compaction "
- << count_ignored_homogeneous_space_compaction_.LoadSequentiallyConsistent()
- << " delayed count = "
- << count_delayed_oom_.LoadSequentiallyConsistent();
+ case kAllocatorTypeNonMoving: {
+ // Try to transition the heap if the allocation failure was due to the space being full.
+ if (!IsOutOfMemoryOnAllocation<false>(allocator, alloc_size)) {
+ // If we aren't out of memory then the OOM was probably from the non moving space being
+ // full. Attempt to disable compaction and turn the main space into a non moving space.
+ DisableMovingGc();
+ // If we are still a moving GC then something must have caused the transition to fail.
+ if (IsMovingGc(collector_type_)) {
+ MutexLock mu(self, *gc_complete_lock_);
+ // If we couldn't disable moving GC, just throw OOME and return null.
+ LOG(WARNING) << "Couldn't disable moving GC with disable GC count "
+ << disable_moving_gc_count_;
+ } else {
+ LOG(WARNING) << "Disabled moving GC due to the non moving space being full";
+ ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated,
+ usable_size);
+ }
+ }
+ break;
+ }
+ default: {
+ // Do nothing for others allocators.
+ }
}
}
// If the allocation hasn't succeeded by this point, throw an OOM error.
@@ -1473,9 +1524,10 @@
WaitForGcToCompleteLocked(kGcCauseHomogeneousSpaceCompact, self);
// Homogeneous space compaction is a copying transition, can't run it if the moving GC disable count
// is non zero.
- // If the collecotr type changed to something which doesn't benefit from homogeneous space compaction,
+ // If the collector type changed to something which doesn't benefit from homogeneous space compaction,
// exit.
- if (disable_moving_gc_count_ != 0 || IsMovingGc(collector_type_)) {
+ if (disable_moving_gc_count_ != 0 || IsMovingGc(collector_type_) ||
+ !main_space_->CanMoveObjects()) {
return HomogeneousSpaceCompactResult::kErrorReject;
}
collector_type_running_ = kCollectorTypeHomogeneousSpaceCompact;
@@ -1534,8 +1586,9 @@
Thread* const self = Thread::Current();
ScopedThreadStateChange tsc(self, kWaitingPerformingGc);
Locks::mutator_lock_->AssertNotHeld(self);
- const bool copying_transition =
- IsMovingGc(background_collector_type_) || IsMovingGc(foreground_collector_type_);
+ // Currently we only need a heap transition if we switch from a moving collector to a non moving
+ // one, or visa versa.
+ const bool copying_transition = IsMovingGc(collector_type_) != IsMovingGc(collector_type);
// Busy wait until we can GC (StartGC can fail if we have a non-zero
// compacting_gc_disable_count_, this should rarely occurs).
for (;;) {
@@ -1835,9 +1888,9 @@
// The end of the non-moving space may be protected, unprotect it so that we can copy the zygote
// there.
non_moving_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE);
- // Change the collector to the post zygote one.
- bool same_space = non_moving_space_ == main_space_;
+ const bool same_space = non_moving_space_ == main_space_;
if (kCompactZygote) {
+ // Can't compact if the non moving space is the same as the main space.
DCHECK(semi_space_collector_ != nullptr);
// Temporarily disable rosalloc verification because the zygote
// compaction will mess up the rosalloc internal metadata.
@@ -1882,6 +1935,7 @@
non_moving_space_->SetLimit(target_space.Limit());
VLOG(heap) << "Zygote space size " << non_moving_space_->Size() << " bytes";
}
+ // Change the collector to the post zygote one.
ChangeCollector(foreground_collector_type_);
// Save the old space so that we can remove it after we complete creating the zygote space.
space::MallocSpace* old_alloc_space = non_moving_space_;