Revert of [heap] Ensure progress when incrementally marking wrappers (patchset #3 id:60001 of https://codereview.chromium.org/2592403002/ )

Reason for revert:
This won't work because the finalization still checks whether both marking deques are empty, also calling into blink. So we never proceed there.

Original issue's description:
> [heap] Ensure progress when incrementally marking wrappers
>
> The problem here is estimating the marking step size for wrapper tracing. If the
> steps are too small, we cannot keep up with the mutator creating new wrappers.
> The result is an endless stream of incremental marking steps, alternating v8 and
> wrappers tracing, without ever finalizing in a GC.
>
> The mitigation here is to abort finding the fix point after 10 incremental
> iterations.
>
> A proper solution would track newly created wrappers on the blink side during
> wrapper tracing. Will give this more thought after the holidays.
>
> BUG=chromium:668164, chromium:468240
>
> Review-Url: https://codereview.chromium.org/2592403002
> Cr-Commit-Position: refs/heads/master@{#41923}
> Committed: a47417b893

TBR=ulan@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:668164, chromium:468240

Review-Url: https://codereview.chromium.org/2602433002
Cr-Commit-Position: refs/heads/master@{#41924}
This commit is contained in:
mlippautz 2016-12-22 07:07:36 -08:00 committed by Commit bot
parent a47417b893
commit 73036fb691
3 changed files with 7 additions and 25 deletions

View File

@ -13,8 +13,6 @@ void LocalEmbedderHeapTracer::TracePrologue() {
if (!InUse()) return;
CHECK(cached_wrappers_to_trace_.empty());
num_v8_marking_deque_was_empty_ = 0;
in_final_pause_ = false;
remote_tracer_->TracePrologue();
}
@ -35,7 +33,6 @@ void LocalEmbedderHeapTracer::AbortTracing() {
void LocalEmbedderHeapTracer::EnterFinalPause() {
if (!InUse()) return;
in_final_pause_ = true;
remote_tracer_->EnterFinalPause();
}
@ -44,10 +41,7 @@ bool LocalEmbedderHeapTracer::Trace(
if (!InUse()) return false;
RegisterWrappersWithRemoteTracer();
return (in_final_pause_ ||
(num_v8_marking_deque_was_empty_ <= kMaxIncrementalMarkingRounds))
? remote_tracer_->AdvanceTracing(deadline, actions)
: false;
return remote_tracer_->AdvanceTracing(deadline, actions);
}
size_t LocalEmbedderHeapTracer::NumberOfWrappersToTrace() {

View File

@ -17,10 +17,7 @@ class V8_EXPORT_PRIVATE LocalEmbedderHeapTracer final {
public:
typedef std::pair<void*, void*> WrapperInfo;
LocalEmbedderHeapTracer()
: remote_tracer_(nullptr),
num_v8_marking_deque_was_empty_(0),
in_final_pause_(false) {}
LocalEmbedderHeapTracer() : remote_tracer_(nullptr) {}
void SetRemoteTracer(EmbedderHeapTracer* tracer) { remote_tracer_ = tracer; }
bool InUse() { return remote_tracer_ != nullptr; }
@ -46,17 +43,11 @@ class V8_EXPORT_PRIVATE LocalEmbedderHeapTracer final {
// are too many of them.
bool RequiresImmediateWrapperProcessing();
void NotifyV8MarkingDequeWasEmpty() { num_v8_marking_deque_was_empty_++; }
private:
typedef std::vector<WrapperInfo> WrapperCache;
static const size_t kMaxIncrementalMarkingRounds = 10;
EmbedderHeapTracer* remote_tracer_;
WrapperCache cached_wrappers_to_trace_;
size_t num_v8_marking_deque_was_empty_;
bool in_final_pause_;
};
} // namespace internal

View File

@ -1137,12 +1137,11 @@ size_t IncrementalMarking::Step(size_t bytes_to_process,
const bool incremental_wrapper_tracing =
FLAG_incremental_marking_wrappers &&
heap_->local_embedder_heap_tracer()->InUse();
const bool v8_marking_deque_empty =
heap_->mark_compact_collector()->marking_deque()->IsEmpty();
const bool process_wrappers = incremental_wrapper_tracing &&
(heap_->local_embedder_heap_tracer()
->RequiresImmediateWrapperProcessing() ||
v8_marking_deque_empty);
const bool process_wrappers =
incremental_wrapper_tracing &&
(heap_->local_embedder_heap_tracer()
->RequiresImmediateWrapperProcessing() ||
heap_->mark_compact_collector()->marking_deque()->IsEmpty());
bool wrapper_work_left = incremental_wrapper_tracing;
if (!process_wrappers) {
bytes_processed = ProcessMarkingDeque(bytes_to_process);
@ -1154,8 +1153,6 @@ size_t IncrementalMarking::Step(size_t bytes_to_process,
heap_->MonotonicallyIncreasingTimeInMs() + kStepSizeInMs;
TRACE_GC(heap()->tracer(),
GCTracer::Scope::MC_INCREMENTAL_WRAPPER_TRACING);
if (v8_marking_deque_empty)
heap_->local_embedder_heap_tracer()->NotifyV8MarkingDequeWasEmpty();
wrapper_work_left = heap_->local_embedder_heap_tracer()->Trace(
wrapper_deadline, EmbedderHeapTracer::AdvanceTracingActions(
EmbedderHeapTracer::ForceCompletionAction::