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[heap] Fix data race when setting COMPACTION_WAS_ABORTED page flag

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When evacuation gets aborted due to OOM we used to set the
COMPACTION_WAS_ABORTED page flag immediately. However other evacuation
threads might check the page flags of that exact page concurrently
while recording slots in migrated objects.

We can delay setting the COMPACTION_WAS_ABORTED page flags until
processing aborted evacuation candidates. At that point there are
no more concurrent evacuation threads running anymore.

In order to not break output of --trace-evacuation we also need a
return value for RawEvacuatePage.

Bug: v8:13336
Change-Id: I29a76af918ee4f2016ab6d7c26c2688ff6a14aae
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3925974
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#83479}
This commit is contained in:
Dominik Inführ 2022-09-28 16:30:34 +02:00 committed by V8 LUCI CQ
parent c4772b58aa
commit d32b5ab97c
1 changed files with 18 additions and 10 deletions
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28
src/heap/mark-compact.cc
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@ -4165,7 +4165,7 @@ class Evacuator : public Malloced {
static const int kInitialLocalPretenuringFeedbackCapacity = 256;
// |saved_live_bytes| returns the live bytes of the page that was processed.
virtual void RawEvacuatePage(MemoryChunk* chunk,
virtual bool RawEvacuatePage(MemoryChunk* chunk,
intptr_t* saved_live_bytes) = 0;
inline Heap* heap() { return heap_; }
@ -4203,10 +4203,11 @@ void Evacuator::EvacuatePage(MemoryChunk* chunk) {
DCHECK(chunk->SweepingDone());
intptr_t saved_live_bytes = 0;
double evacuation_time = 0.0;
bool success = false;
{
AlwaysAllocateScope always_allocate(heap());
TimedScope timed_scope(&evacuation_time);
RawEvacuatePage(chunk, &saved_live_bytes);
success = RawEvacuatePage(chunk, &saved_live_bytes);
}
ReportCompactionProgress(evacuation_time, saved_live_bytes);
if (v8_flags.trace_evacuation) {
@ -4220,8 +4221,7 @@ void Evacuator::EvacuatePage(MemoryChunk* chunk) {
chunk->IsFlagSet(Page::PAGE_NEW_NEW_PROMOTION),
chunk->IsFlagSet(MemoryChunk::IS_EXECUTABLE),
heap()->new_space()->IsPromotionCandidate(chunk),
saved_live_bytes, evacuation_time,
chunk->IsFlagSet(Page::COMPACTION_WAS_ABORTED));
saved_live_bytes, evacuation_time, success);
}
}
@ -4278,7 +4278,7 @@ class FullEvacuator : public Evacuator {
}
protected:
void RawEvacuatePage(MemoryChunk* chunk, intptr_t* live_bytes) override;
bool RawEvacuatePage(MemoryChunk* chunk, intptr_t* live_bytes) override;
EphemeronRememberedSet ephemeron_remembered_set_;
RecordMigratedSlotVisitor record_visitor_;
@ -4287,7 +4287,7 @@ class FullEvacuator : public Evacuator {
MarkCompactCollector* collector_;
};
void FullEvacuator::RawEvacuatePage(MemoryChunk* chunk, intptr_t* live_bytes) {
bool FullEvacuator::RawEvacuatePage(MemoryChunk* chunk, intptr_t* live_bytes) {
const EvacuationMode evacuation_mode = ComputeEvacuationMode(chunk);
NonAtomicMarkingState* marking_state = collector_->non_atomic_marking_state();
*live_bytes = marking_state->live_bytes(chunk);
@ -4336,11 +4336,14 @@ void FullEvacuator::RawEvacuatePage(MemoryChunk* chunk, intptr_t* live_bytes) {
// thread for simplicity reasons.
collector_->ReportAbortedEvacuationCandidateDueToOOM(
failed_object.address(), static_cast<Page*>(chunk));
return false;
}
}
break;
}
}
return true;
}
class PageEvacuationJob : public v8::JobTask {
@ -5360,8 +5363,6 @@ void MarkCompactCollector::UpdatePointersInClientHeap(Isolate* client) {
void MarkCompactCollector::ReportAbortedEvacuationCandidateDueToOOM(
Address failed_start, Page* page) {
DCHECK(!page->IsFlagSet(Page::COMPACTION_WAS_ABORTED));
page->SetFlag(Page::COMPACTION_WAS_ABORTED);
base::MutexGuard guard(&mutex_);
aborted_evacuation_candidates_due_to_oom_.push_back(
std::make_pair(failed_start, page));
@ -5427,6 +5428,11 @@ void ReRecordPage(Heap* heap,
size_t MarkCompactCollector::PostProcessAbortedEvacuationCandidates() {
CHECK_IMPLIES(v8_flags.crash_on_aborted_evacuation,
aborted_evacuation_candidates_due_to_oom_.empty());
for (auto start_and_page : aborted_evacuation_candidates_due_to_oom_) {
Page* page = start_and_page.second;
DCHECK(!page->IsFlagSet(Page::COMPACTION_WAS_ABORTED));
page->SetFlag(Page::COMPACTION_WAS_ABORTED);
}
for (auto start_and_page : aborted_evacuation_candidates_due_to_oom_) {
ReRecordPage(heap(), non_atomic_marking_state(), start_and_page.first,
start_and_page.second);
@ -6597,14 +6603,14 @@ class YoungGenerationEvacuator : public Evacuator {
}
protected:
void RawEvacuatePage(MemoryChunk* chunk, intptr_t* live_bytes) override;
bool RawEvacuatePage(MemoryChunk* chunk, intptr_t* live_bytes) override;
YoungGenerationRecordMigratedSlotVisitor record_visitor_;
EvacuationAllocator local_allocator_;
MinorMarkCompactCollector* collector_;
};
void YoungGenerationEvacuator::RawEvacuatePage(MemoryChunk* chunk,
bool YoungGenerationEvacuator::RawEvacuatePage(MemoryChunk* chunk,
intptr_t* live_bytes) {
TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.gc"),
"YoungGenerationEvacuator::RawEvacuatePage");
@ -6628,6 +6634,8 @@ void YoungGenerationEvacuator::RawEvacuatePage(MemoryChunk* chunk,
FreeSpaceTreatmentMode::kIgnoreFreeSpace);
}
}
return true;
}
} // namespace