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Revert of [heap] Better integrate handling of aborted compaction pages (patchset #7 id:130001 of https://codereview.chromium.org/1881423003/ )

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Reason for revert:
Breaks: https://uberchromegw.corp.google.com/i/client.v8.ports/builders/V8%20Linux%20-%20arm64%20-%20sim%20-%20nosnap%20-%20debug/builds/20

RecordMigratedSlotVisitor is not safe to use on code pages.

Original issue's description:
> [heap] Better integrate handling of aborted compaction pages
>
> - Get rid of fixing up pointers on the main thread
> - Get rid of sweeping on the main thread
>
> Instead:
> - Record (and process afterwards) slots in parallel
> - Add the pages to the concurrent sweeper as pointers have already been fixed
>
> BUG=chromium:581412
> LOG=N
> TEST=cctest/test-compaction/*
>
> Committed: https://crrev.com/2e4f57774d4993f9f98332d3b2469280ee10beca
> Cr-Commit-Position: refs/heads/master@{#35451}

TBR=hpayer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:581412

Review URL: https://codereview.chromium.org/1890553002

Cr-Commit-Position: refs/heads/master@{#35454}
This commit is contained in:
mlippautz 2016-04-13 11:45:09 -07:00 committed by Commit bot
parent 5e9ddf6ce4
commit 6df04b296b
4 changed files with 62 additions and 40 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

89
src/heap/mark-compact.cc
View File

@ -1818,15 +1818,6 @@ class MarkCompactCollector::EvacuateOldSpaceVisitor final
}
};
class MarkCompactCollector::EvacuateRecordOnlyVisitor final
: public MarkCompactCollector::HeapObjectVisitor {
public:
bool Visit(HeapObject* object) {
RecordMigratedSlotVisitor visitor;
object->IterateBodyFast(&visitor);
return true;
}
};
void MarkCompactCollector::DiscoverGreyObjectsInSpace(PagedSpace* space) {
PageIterator it(space);
@ -3101,17 +3092,6 @@ bool MarkCompactCollector::Evacuator::EvacuatePage(MemoryChunk* chunk) {
DCHECK(chunk->IsEvacuationCandidate());
DCHECK_EQ(chunk->concurrent_sweeping_state().Value(), Page::kSweepingDone);
success = EvacuateSinglePage<kClearMarkbits>(chunk, &old_space_visitor_);
if (!success) {
// Aborted compaction page. We can record slots here to have them
// processed in parallel later on.
EvacuateRecordOnlyVisitor record_visitor;
success = EvacuateSinglePage<kKeepMarking>(chunk, &record_visitor);
DCHECK(success);
USE(success);
// We need to return failure here to indicate that we want this page added
// to the sweeper.
return false;
}
}
return success;
}
@ -3172,8 +3152,8 @@ class EvacuationJobTraits {
return evacuator->EvacuatePage(chunk);
}
static void FinalizePageSequentially(Heap* heap, MemoryChunk* chunk,
bool success, PerPageData data) {
static void FinalizePageSequentially(Heap*, MemoryChunk* chunk, bool success,
PerPageData data) {
if (chunk->InNewSpace()) {
DCHECK(success);
} else {
@ -3185,12 +3165,17 @@ class EvacuationJobTraits {
} else {
// We have partially compacted the page, i.e., some objects may have
// moved, others are still in place.
// We need to:
// - Leave the evacuation candidate flag for later processing of slots
// buffer entries.
// - Leave the slots buffer there for processing of entries added by
// the write barrier.
// - Rescan the page as slot recording in the migration buffer only
// happens upon moving (which we potentially didn't do).
// - Leave the page in the list of pages of a space since we could not
// fully evacuate it.
DCHECK(p->IsEvacuationCandidate());
p->SetFlag(Page::COMPACTION_WAS_ABORTED);
p->ClearEvacuationCandidate();
// Slots have already been recorded so we just need to add it to the
// sweeper.
heap->mark_compact_collector()->sweeper().AddLatePage(
p->owner()->identity(), p);
*data += 1;
}
}
@ -3434,6 +3419,42 @@ void MarkCompactCollector::Sweeper::AddSweptPageSafe(PagedSpace* space,
swept_list_[space->identity()].Add(page);
}
void MarkCompactCollector::SweepAbortedPages() {
// Second pass on aborted pages.
for (Page* p : evacuation_candidates_) {
if (p->IsFlagSet(Page::COMPACTION_WAS_ABORTED)) {
p->ClearFlag(MemoryChunk::COMPACTION_WAS_ABORTED);
p->concurrent_sweeping_state().SetValue(Page::kSweepingInProgress);
PagedSpace* space = static_cast<PagedSpace*>(p->owner());
switch (space->identity()) {
case OLD_SPACE:
Sweeper::RawSweep<Sweeper::SWEEP_ONLY, Sweeper::SWEEP_ON_MAIN_THREAD,
Sweeper::IGNORE_SKIP_LIST,
Sweeper::IGNORE_FREE_SPACE>(space, p, nullptr);
break;
case CODE_SPACE:
if (FLAG_zap_code_space) {
Sweeper::RawSweep<
Sweeper::SWEEP_ONLY, Sweeper::SWEEP_ON_MAIN_THREAD,
Sweeper::REBUILD_SKIP_LIST, Sweeper::ZAP_FREE_SPACE>(space, p,
nullptr);
} else {
Sweeper::RawSweep<
Sweeper::SWEEP_ONLY, Sweeper::SWEEP_ON_MAIN_THREAD,
Sweeper::REBUILD_SKIP_LIST, Sweeper::IGNORE_FREE_SPACE>(
space, p, nullptr);
}
break;
default:
UNREACHABLE();
break;
}
sweeper().AddSweptPageSafe(space, p);
}
}
}
void MarkCompactCollector::EvacuateNewSpaceAndCandidates() {
TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_EVACUATE);
Heap::RelocationLock relocation_lock(heap());
@ -3458,6 +3479,9 @@ void MarkCompactCollector::EvacuateNewSpaceAndCandidates() {
{
TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_EVACUATE_CLEAN_UP);
// After updating all pointers, we can finally sweep the aborted pages,
// effectively overriding any forward pointers.
SweepAbortedPages();
// EvacuateNewSpaceAndCandidates iterates over new space objects and for
// ArrayBuffers either re-registers them as live or promotes them. This is
@ -3615,15 +3639,18 @@ void MarkCompactCollector::UpdatePointersAfterEvacuation() {
TRACE_GC(heap()->tracer(),
GCTracer::Scope::MC_EVACUATE_UPDATE_POINTERS_BETWEEN_EVACUATED);
for (Page* p : evacuation_candidates_) {
if (p->IsFlagSet(Page::COMPACTION_WAS_ABORTED)) {
p->ClearFlag(Page::COMPACTION_WAS_ABORTED);
}
if (!p->IsEvacuationCandidate()) continue;
DCHECK(p->IsEvacuationCandidate());
// Important: skip list should be cleared only after roots were updated
// because root iteration traverses the stack and might have to find
// code objects from non-updated pc pointing into evacuation candidate.
SkipList* list = p->skip_list();
if (list != NULL) list->Clear();
// First pass on aborted pages, fixing up all live objects.
if (p->IsFlagSet(Page::COMPACTION_WAS_ABORTED)) {
p->ClearEvacuationCandidate();
VisitLiveObjectsBody(p, &updating_visitor);
}
}
}

3
src/heap/mark-compact.h
View File

@ -630,7 +630,6 @@ class MarkCompactCollector {
private:
class EvacuateNewSpaceVisitor;
class EvacuateOldSpaceVisitor;
class EvacuateRecordOnlyVisitor;
class EvacuateVisitorBase;
class HeapObjectVisitor;
@ -835,6 +834,8 @@ class MarkCompactCollector {
void RecomputeLiveBytes(MemoryChunk* page);
void SweepAbortedPages();
void ReleaseEvacuationCandidates();
// Starts sweeping of a space by contributing on the main thread and setting

6
src/heap/spaces-inl.h
View File

@ -382,10 +382,8 @@ void Page::MarkEvacuationCandidate() {
}
void Page::ClearEvacuationCandidate() {
if (!IsFlagSet(COMPACTION_WAS_ABORTED)) {
DCHECK_NULL(old_to_old_slots_);
DCHECK_NULL(typed_old_to_old_slots_);
}
DCHECK_NULL(old_to_old_slots_);
DCHECK_NULL(typed_old_to_old_slots_);
ClearFlag(EVACUATION_CANDIDATE);
InitializeFreeListCategories();
}

4
test/cctest/heap/test-compaction.cc
View File

@ -50,7 +50,6 @@ HEAP_TEST(CompactionFullAbortedPage) {
heap->set_force_oom(true);
heap->CollectAllGarbage();
heap->mark_compact_collector()->EnsureSweepingCompleted();
// Check that all handles still point to the same page, i.e., compaction
// has been aborted on the page.
@ -109,7 +108,6 @@ HEAP_TEST(CompactionPartiallyAbortedPage) {
heap->set_force_oom(true);
heap->CollectAllGarbage();
heap->mark_compact_collector()->EnsureSweepingCompleted();
bool migration_aborted = false;
for (Handle<FixedArray> object : compaction_page_handles) {
@ -192,7 +190,6 @@ HEAP_TEST(CompactionPartiallyAbortedPageIntraAbortedPointers) {
heap->set_force_oom(true);
heap->CollectAllGarbage();
heap->mark_compact_collector()->EnsureSweepingCompleted();
// The following check makes sure that we compacted "some" objects, while
// leaving others in place.
@ -286,7 +283,6 @@ HEAP_TEST(CompactionPartiallyAbortedPageWithStoreBufferEntries) {
heap->set_force_oom(true);
heap->CollectAllGarbage();
heap->mark_compact_collector()->EnsureSweepingCompleted();
// The following check makes sure that we compacted "some" objects, while
// leaving others in place.