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src/hotspot/share/gc/g1/g1ParScanThreadState.cpp
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rev 60435 : imported patch improve_inlining
rev 60436 : imported patch allocate_copy_slow
@@ -153,15 +153,135 @@
ShouldNotReachHere();
}
}
#endif // ASSERT
-void G1ParScanThreadState::trim_queue() {
+template <class T> void G1ParScanThreadState::do_oop_evac(T* p) {
+ // Reference should not be NULL here as such are never pushed to the task queue.
+ oop obj = RawAccess<IS_NOT_NULL>::oop_load(p);
+
+ // Although we never intentionally push references outside of the collection
+ // set, due to (benign) races in the claim mechanism during RSet scanning more
+ // than one thread might claim the same card. So the same card may be
+ // processed multiple times, and so we might get references into old gen here.
+ // So we need to redo this check.
+ const G1HeapRegionAttr region_attr = _g1h->region_attr(obj);
+ // References pushed onto the work stack should never point to a humongous region
+ // as they are not added to the collection set due to above precondition.
+ assert(!region_attr.is_humongous(),
+ "Obj " PTR_FORMAT " should not refer to humongous region %u from " PTR_FORMAT,
+ p2i(obj), _g1h->addr_to_region(cast_from_oop<HeapWord*>(obj)), p2i(p));
+
+ if (!region_attr.is_in_cset()) {
+ // In this case somebody else already did all the work.
+ return;
+ }
+
+ markWord m = obj->mark_raw();
+ if (m.is_marked()) {
+ obj = (oop) m.decode_pointer();
+ } else {
+ obj = do_copy_to_survivor_space(region_attr, obj, m);
+ }
+ RawAccess<IS_NOT_NULL>::oop_store(p, obj);
+
+ assert(obj != NULL, "Must be");
+ if (HeapRegion::is_in_same_region(p, obj)) {
+ return;
+ }
+ HeapRegion* from = _g1h->heap_region_containing(p);
+ if (!from->is_young()) {
+ enqueue_card_if_tracked(_g1h->region_attr(obj), p, obj);
+ }
+}
+
+void G1ParScanThreadState::do_partial_array(PartialArrayScanTask task) {
+ oop from_obj = task.to_source_array();
+
+ assert(_g1h->is_in_reserved(from_obj), "must be in heap.");
+ assert(from_obj->is_objArray(), "must be obj array");
+ objArrayOop from_obj_array = objArrayOop(from_obj);
+ // The from-space object contains the real length.
+ int length = from_obj_array->length();
+
+ assert(from_obj->is_forwarded(), "must be forwarded");
+ oop to_obj = from_obj->forwardee();
+ assert(from_obj != to_obj, "should not be chunking self-forwarded objects");
+ objArrayOop to_obj_array = objArrayOop(to_obj);
+ // We keep track of the next start index in the length field of the
+ // to-space object.
+ int next_index = to_obj_array->length();
+ assert(0 <= next_index && next_index < length,
+ "invariant, next index: %d, length: %d", next_index, length);
+
+ int start = next_index;
+ int end = length;
+ int remainder = end - start;
+ // We'll try not to push a range that's smaller than ParGCArrayScanChunk.
+ if (remainder > 2 * ParGCArrayScanChunk) {
+ end = start + ParGCArrayScanChunk;
+ to_obj_array->set_length(end);
+ // Push the remainder before we process the range in case another
+ // worker has run out of things to do and can steal it.
+ push_on_queue(ScannerTask(PartialArrayScanTask(from_obj)));
+ } else {
+ assert(length == end, "sanity");
+ // We'll process the final range for this object. Restore the length
+ // so that the heap remains parsable in case of evacuation failure.
+ to_obj_array->set_length(end);
+ }
+
+ HeapRegion* hr = _g1h->heap_region_containing(to_obj);
+ G1ScanInYoungSetter x(&_scanner, hr->is_young());
+ // Process indexes [start,end). It will also process the header
+ // along with the first chunk (i.e., the chunk with start == 0).
+ // Note that at this point the length field of to_obj_array is not
+ // correct given that we are using it to keep track of the next
+ // start index. oop_iterate_range() (thankfully!) ignores the length
+ // field and only relies on the start / end parameters. It does
+ // however return the size of the object which will be incorrect. So
+ // we have to ignore it even if we wanted to use it.
+ to_obj_array->oop_iterate_range(&_scanner, start, end);
+}
+
+void G1ParScanThreadState::dispatch_task(ScannerTask task) {
+ verify_task(task);
+ if (task.is_narrow_oop_ptr()) {
+ do_oop_evac(task.to_narrow_oop_ptr());
+ } else if (task.is_oop_ptr()) {
+ do_oop_evac(task.to_oop_ptr());
+ } else {
+ do_partial_array(task.to_partial_array_task());
+ }
+}
+
+// Process tasks until overflow queue is empty and local queue
+// contains no more than threshold entries. NOINLINE to prevent
+// inlining into steal_and_trim_queue.
+ATTRIBUTE_FLATTEN NOINLINE
+void G1ParScanThreadState::trim_queue_to_threshold(uint threshold) {
+ ScannerTask task;
do {
- // Fully drain the queue.
- trim_queue_to_threshold(0);
- } while (!_task_queue->is_empty());
+ while (_task_queue->pop_overflow(task)) {
+ if (!_task_queue->try_push_to_taskqueue(task)) {
+ dispatch_task(task);
+ }
+ }
+ while (_task_queue->pop_local(task, threshold)) {
+ dispatch_task(task);
+ }
+ } while (!_task_queue->overflow_empty());
+}
+
+ATTRIBUTE_FLATTEN
+void G1ParScanThreadState::steal_and_trim_queue(G1ScannerTasksQueueSet* task_queues) {
+ ScannerTask stolen_task;
+ while (task_queues->steal(_worker_id, stolen_task)) {
+ dispatch_task(stolen_task);
+ // Processing stolen task may have added tasks to our queue.
+ trim_queue();
+ }
}
HeapWord* G1ParScanThreadState::allocate_in_next_plab(G1HeapRegionAttr* dest,
size_t word_sz,
bool previous_plab_refill_failed,
@@ -225,58 +345,86 @@
_g1h->_gc_tracer_stw->report_promotion_outside_plab_event(old->klass(), word_sz * HeapWordSize, age,
dest_attr.type() == G1HeapRegionAttr::Old);
}
}
-oop G1ParScanThreadState::copy_to_survivor_space(G1HeapRegionAttr const region_attr,
+NOINLINE
+HeapWord* G1ParScanThreadState::allocate_copy_slow(G1HeapRegionAttr* dest_attr,
+ oop old,
+ size_t word_sz,
+ uint age,
+ uint node_index) {
+ HeapWord* obj_ptr = NULL;
+ // Try slow-path allocation unless we're allocating old and old is already full.
+ if (!(dest_attr->is_old() && _old_gen_is_full)) {
+ bool plab_refill_failed = false;
+ obj_ptr = _plab_allocator->allocate_direct_or_new_plab(*dest_attr,
+ word_sz,
+ &plab_refill_failed,
+ node_index);
+ if (obj_ptr == NULL) {
+ obj_ptr = allocate_in_next_plab(dest_attr,
+ word_sz,
+ plab_refill_failed,
+ node_index);
+ }
+ }
+ if (obj_ptr != NULL) {
+ update_numa_stats(node_index);
+ if (_g1h->_gc_tracer_stw->should_report_promotion_events()) {
+ // The events are checked individually as part of the actual commit
+ report_promotion_event(*dest_attr, old, word_sz, age, obj_ptr, node_index);
+ }
+ }
+ return obj_ptr;
+}
+
+NOINLINE
+void G1ParScanThreadState::undo_allocation(G1HeapRegionAttr dest_attr,
+ HeapWord* obj_ptr,
+ size_t word_sz,
+ uint node_index) {
+ _plab_allocator->undo_allocation(dest_attr, obj_ptr, word_sz, node_index);
+}
+
+// Private inline function, for direct internal use and providing the
+// implementation of the public not-inline function.
+oop G1ParScanThreadState::do_copy_to_survivor_space(G1HeapRegionAttr const region_attr,
oop const old,
markWord const old_mark) {
+ assert(region_attr.is_in_cset(),
+ "Unexpected region attr type: %s", region_attr.get_type_str());
+
const size_t word_sz = old->size();
uint age = 0;
G1HeapRegionAttr dest_attr = next_region_attr(region_attr, old_mark, age);
- // The second clause is to prevent premature evacuation failure in case there
- // is still space in survivor, but old gen is full.
- if (_old_gen_is_full && dest_attr.is_old()) {
- return handle_evacuation_failure_par(old, old_mark);
- }
HeapRegion* const from_region = _g1h->heap_region_containing(old);
uint node_index = from_region->node_index();
HeapWord* obj_ptr = _plab_allocator->plab_allocate(dest_attr, word_sz, node_index);
// PLAB allocations should succeed most of the time, so we'll
// normally check against NULL once and that's it.
if (obj_ptr == NULL) {
- bool plab_refill_failed = false;
- obj_ptr = _plab_allocator->allocate_direct_or_new_plab(dest_attr, word_sz, &plab_refill_failed, node_index);
- if (obj_ptr == NULL) {
- assert(region_attr.is_in_cset(), "Unexpected region attr type: %s", region_attr.get_type_str());
- obj_ptr = allocate_in_next_plab(&dest_attr, word_sz, plab_refill_failed, node_index);
+ obj_ptr = allocate_copy_slow(&dest_attr, old, word_sz, age, node_index);
if (obj_ptr == NULL) {
// This will either forward-to-self, or detect that someone else has
// installed a forwarding pointer.
return handle_evacuation_failure_par(old, old_mark);
}
}
- update_numa_stats(node_index);
-
- if (_g1h->_gc_tracer_stw->should_report_promotion_events()) {
- // The events are checked individually as part of the actual commit
- report_promotion_event(dest_attr, old, word_sz, age, obj_ptr, node_index);
- }
- }
assert(obj_ptr != NULL, "when we get here, allocation should have succeeded");
assert(_g1h->is_in_reserved(obj_ptr), "Allocated memory should be in the heap");
#ifndef PRODUCT
// Should this evacuation fail?
if (_g1h->evacuation_should_fail()) {
// Doing this after all the allocation attempts also tests the
// undo_allocation() method too.
- _plab_allocator->undo_allocation(dest_attr, obj_ptr, word_sz, node_index);
+ undo_allocation(dest_attr, obj_ptr, word_sz, node_index);
return handle_evacuation_failure_par(old, old_mark);
}
#endif // !PRODUCT
// We're going to allocate linearly, so might as well prefetch ahead.
@@ -285,14 +433,16 @@
const oop obj = oop(obj_ptr);
const oop forward_ptr = old->forward_to_atomic(obj, old_mark, memory_order_relaxed);
if (forward_ptr == NULL) {
Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(old), obj_ptr, word_sz);
+ {
const uint young_index = from_region->young_index_in_cset();
-
assert((from_region->is_young() && young_index > 0) ||
(!from_region->is_young() && young_index == 0), "invariant" );
+ _surviving_young_words[young_index] += word_sz;
+ }
if (dest_attr.is_young()) {
if (age < markWord::max_age) {
age++;
}
@@ -322,12 +472,10 @@
is_to_young,
_worker_id,
obj);
}
- _surviving_young_words[young_index] += word_sz;
-
if (obj->is_objArray() && arrayOop(obj)->length() >= ParGCArrayScanChunk) {
// We keep track of the next start index in the length field of
// the to-space object. The actual length can be found in the
// length field of the from-space object.
arrayOop(obj)->set_length(0);
@@ -341,10 +489,18 @@
_plab_allocator->undo_allocation(dest_attr, obj_ptr, word_sz, node_index);
return forward_ptr;
}
}
+// Public not-inline entry point.
+ATTRIBUTE_FLATTEN
+oop G1ParScanThreadState::copy_to_survivor_space(G1HeapRegionAttr region_attr,
+ oop old,
+ markWord old_mark) {
+ return do_copy_to_survivor_space(region_attr, old, old_mark);
+}
+
G1ParScanThreadState* G1ParScanThreadStateSet::state_for_worker(uint worker_id) {
assert(worker_id < _n_workers, "out of bounds access");
if (_states[worker_id] == NULL) {
_states[worker_id] =
new G1ParScanThreadState(_g1h, _rdcqs, worker_id, _young_cset_length, _optional_cset_length);
@@ -396,10 +552,11 @@
size_t used_memory = pss->oops_into_optional_region(hr)->used_memory();
_g1h->phase_times()->record_or_add_thread_work_item(G1GCPhaseTimes::OptScanHR, worker_index, used_memory, G1GCPhaseTimes::ScanHRUsedMemory);
}
}
+NOINLINE
oop G1ParScanThreadState::handle_evacuation_failure_par(oop old, markWord m) {
assert(_g1h->is_in_cset(old), "Object " PTR_FORMAT " should be in the CSet", p2i(old));
oop forward_ptr = old->forward_to_atomic(old, m, memory_order_relaxed);
if (forward_ptr == NULL) {
@@ -426,10 +583,37 @@
"should not be in the CSet",
p2i(old), p2i(forward_ptr));
return forward_ptr;
}
}
+
+void G1ParScanThreadState::initialize_numa_stats() {
+ if (_numa->is_enabled()) {
+ LogTarget(Info, gc, heap, numa) lt;
+
+ if (lt.is_enabled()) {
+ uint num_nodes = _numa->num_active_nodes();
+ // Record only if there are multiple active nodes.
+ _obj_alloc_stat = NEW_C_HEAP_ARRAY(size_t, num_nodes, mtGC);
+ memset(_obj_alloc_stat, 0, sizeof(size_t) * num_nodes);
+ }
+ }
+}
+
+void G1ParScanThreadState::flush_numa_stats() {
+ if (_obj_alloc_stat != NULL) {
+ uint node_index = _numa->index_of_current_thread();
+ _numa->copy_statistics(G1NUMAStats::LocalObjProcessAtCopyToSurv, node_index, _obj_alloc_stat);
+ }
+}
+
+void G1ParScanThreadState::update_numa_stats(uint node_index) {
+ if (_obj_alloc_stat != NULL) {
+ _obj_alloc_stat[node_index]++;
+ }
+}
+
G1ParScanThreadStateSet::G1ParScanThreadStateSet(G1CollectedHeap* g1h,
G1RedirtyCardsQueueSet* rdcqs,
uint n_workers,
size_t young_cset_length,
size_t optional_cset_length) :
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