7121496: G1: do the per-region evacuation failure handling work in parallel
Summary: Parallelize the removal of self forwarding pointers etc. by wrapping in a HeapRegion closure, which is then wrapped inside an AbstractGangTask.
Reviewed-by: tonyp, iveresov
--- a/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp Thu Jan 05 21:21:55 2012 -0800
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp Fri Dec 23 11:14:18 2011 -0800
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -3080,19 +3080,6 @@
}
};
-class SetClaimValuesInCSetHRClosure: public HeapRegionClosure {
- jint _claim_value;
-
-public:
- SetClaimValuesInCSetHRClosure(jint claim_value) :
- _claim_value(claim_value) { }
-
- bool doHeapRegion(HeapRegion* hr) {
- hr->set_claim_value(_claim_value);
- return false;
- }
-};
-
class G1ParCompleteMarkInCSetTask: public AbstractGangTask {
protected:
G1CollectedHeap* _g1h;
@@ -3135,9 +3122,8 @@
assert(g1h->check_cset_heap_region_claim_values(HeapRegion::CompleteMarkCSetClaimValue), "sanity");
- // Now reset the claim values in the regions in the collection set.
- SetClaimValuesInCSetHRClosure set_cv_cl(HeapRegion::InitialClaimValue);
- g1h->collection_set_iterate(&set_cv_cl);
+ // Reset the claim values in the regions in the collection set.
+ g1h->reset_cset_heap_region_claim_values();
assert(g1h->check_cset_heap_region_claim_values(HeapRegion::InitialClaimValue), "sanity");
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Thu Jan 05 21:21:55 2012 -0800
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Fri Dec 23 11:14:18 2011 -0800
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -32,6 +32,7 @@
#include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
#include "gc_implementation/g1/g1CollectorPolicy.hpp"
#include "gc_implementation/g1/g1ErgoVerbose.hpp"
+#include "gc_implementation/g1/g1EvacFailure.hpp"
#include "gc_implementation/g1/g1MarkSweep.hpp"
#include "gc_implementation/g1/g1OopClosures.inline.hpp"
#include "gc_implementation/g1/g1RemSet.inline.hpp"
@@ -2618,12 +2619,16 @@
}
};
-void
-G1CollectedHeap::reset_heap_region_claim_values() {
+void G1CollectedHeap::reset_heap_region_claim_values() {
ResetClaimValuesClosure blk;
heap_region_iterate(&blk);
}
+void G1CollectedHeap::reset_cset_heap_region_claim_values() {
+ ResetClaimValuesClosure blk;
+ collection_set_iterate(&blk);
+}
+
#ifdef ASSERT
// This checks whether all regions in the heap have the correct claim
// value. I also piggy-backed on this a check to ensure that the
@@ -3998,157 +4003,26 @@
_evac_failure_scan_stack = NULL;
}
-class UpdateRSetDeferred : public OopsInHeapRegionClosure {
-private:
- G1CollectedHeap* _g1;
- DirtyCardQueue *_dcq;
- CardTableModRefBS* _ct_bs;
-
-public:
- UpdateRSetDeferred(G1CollectedHeap* g1, DirtyCardQueue* dcq) :
- _g1(g1), _ct_bs((CardTableModRefBS*)_g1->barrier_set()), _dcq(dcq) {}
-
- virtual void do_oop(narrowOop* p) { do_oop_work(p); }
- virtual void do_oop( oop* p) { do_oop_work(p); }
- template <class T> void do_oop_work(T* p) {
- assert(_from->is_in_reserved(p), "paranoia");
- if (!_from->is_in_reserved(oopDesc::load_decode_heap_oop(p)) &&
- !_from->is_survivor()) {
- size_t card_index = _ct_bs->index_for(p);
- if (_ct_bs->mark_card_deferred(card_index)) {
- _dcq->enqueue((jbyte*)_ct_bs->byte_for_index(card_index));
- }
- }
- }
-};
-
-class RemoveSelfPointerClosure: public ObjectClosure {
-private:
- G1CollectedHeap* _g1;
- ConcurrentMark* _cm;
- HeapRegion* _hr;
- size_t _prev_marked_bytes;
- size_t _next_marked_bytes;
- OopsInHeapRegionClosure *_cl;
-public:
- RemoveSelfPointerClosure(G1CollectedHeap* g1, HeapRegion* hr,
- OopsInHeapRegionClosure* cl) :
- _g1(g1), _hr(hr), _cm(_g1->concurrent_mark()), _prev_marked_bytes(0),
- _next_marked_bytes(0), _cl(cl) {}
-
- size_t prev_marked_bytes() { return _prev_marked_bytes; }
- size_t next_marked_bytes() { return _next_marked_bytes; }
-
- // <original comment>
- // The original idea here was to coalesce evacuated and dead objects.
- // However that caused complications with the block offset table (BOT).
- // In particular if there were two TLABs, one of them partially refined.
- // |----- TLAB_1--------|----TLAB_2-~~~(partially refined part)~~~|
- // The BOT entries of the unrefined part of TLAB_2 point to the start
- // of TLAB_2. If the last object of the TLAB_1 and the first object
- // of TLAB_2 are coalesced, then the cards of the unrefined part
- // would point into middle of the filler object.
- // The current approach is to not coalesce and leave the BOT contents intact.
- // </original comment>
- //
- // We now reset the BOT when we start the object iteration over the
- // region and refine its entries for every object we come across. So
- // the above comment is not really relevant and we should be able
- // to coalesce dead objects if we want to.
- void do_object(oop obj) {
- HeapWord* obj_addr = (HeapWord*) obj;
- assert(_hr->is_in(obj_addr), "sanity");
- size_t obj_size = obj->size();
- _hr->update_bot_for_object(obj_addr, obj_size);
- if (obj->is_forwarded() && obj->forwardee() == obj) {
- // The object failed to move.
- assert(!_g1->is_obj_dead(obj), "We should not be preserving dead objs.");
- _cm->markPrev(obj);
- assert(_cm->isPrevMarked(obj), "Should be marked!");
- _prev_marked_bytes += (obj_size * HeapWordSize);
- if (_g1->mark_in_progress() && !_g1->is_obj_ill(obj)) {
- _cm->markAndGrayObjectIfNecessary(obj);
- }
- obj->set_mark(markOopDesc::prototype());
- // While we were processing RSet buffers during the
- // collection, we actually didn't scan any cards on the
- // collection set, since we didn't want to update remebered
- // sets with entries that point into the collection set, given
- // that live objects fromthe collection set are about to move
- // and such entries will be stale very soon. This change also
- // dealt with a reliability issue which involved scanning a
- // card in the collection set and coming across an array that
- // was being chunked and looking malformed. The problem is
- // that, if evacuation fails, we might have remembered set
- // entries missing given that we skipped cards on the
- // collection set. So, we'll recreate such entries now.
- obj->oop_iterate(_cl);
- assert(_cm->isPrevMarked(obj), "Should be marked!");
- } else {
- // The object has been either evacuated or is dead. Fill it with a
- // dummy object.
- MemRegion mr((HeapWord*)obj, obj_size);
- CollectedHeap::fill_with_object(mr);
- _cm->clearRangeBothMaps(mr);
- }
- }
-};
-
void G1CollectedHeap::remove_self_forwarding_pointers() {
- UpdateRSetImmediate immediate_update(_g1h->g1_rem_set());
- DirtyCardQueue dcq(&_g1h->dirty_card_queue_set());
- UpdateRSetDeferred deferred_update(_g1h, &dcq);
- OopsInHeapRegionClosure *cl;
- if (G1DeferredRSUpdate) {
- cl = &deferred_update;
+ assert(check_cset_heap_region_claim_values(HeapRegion::InitialClaimValue), "sanity");
+ assert(g1_policy()->assertMarkedBytesDataOK(), "Should be!");
+
+ G1ParRemoveSelfForwardPtrsTask rsfp_task(this);
+
+ if (G1CollectedHeap::use_parallel_gc_threads()) {
+ set_par_threads();
+ workers()->run_task(&rsfp_task);
+ set_par_threads(0);
} else {
- cl = &immediate_update;
- }
- HeapRegion* cur = g1_policy()->collection_set();
- while (cur != NULL) {
- assert(g1_policy()->assertMarkedBytesDataOK(), "Should be!");
- assert(!cur->isHumongous(), "sanity");
-
- if (cur->evacuation_failed()) {
- assert(cur->in_collection_set(), "bad CS");
- RemoveSelfPointerClosure rspc(_g1h, cur, cl);
-
- // In the common case we make sure that this is done when the
- // region is freed so that it is "ready-to-go" when it's
- // re-allocated. However, when evacuation failure happens, a
- // region will remain in the heap and might ultimately be added
- // to a CSet in the future. So we have to be careful here and
- // make sure the region's RSet is ready for parallel iteration
- // whenever this might be required in the future.
- cur->rem_set()->reset_for_par_iteration();
- cur->reset_bot();
- cl->set_region(cur);
- cur->object_iterate(&rspc);
-
- // A number of manipulations to make the TAMS be the current top,
- // and the marked bytes be the ones observed in the iteration.
- if (_g1h->concurrent_mark()->at_least_one_mark_complete()) {
- // The comments below are the postconditions achieved by the
- // calls. Note especially the last such condition, which says that
- // the count of marked bytes has been properly restored.
- cur->note_start_of_marking(false);
- // _next_top_at_mark_start == top, _next_marked_bytes == 0
- cur->add_to_marked_bytes(rspc.prev_marked_bytes());
- // _next_marked_bytes == prev_marked_bytes.
- cur->note_end_of_marking();
- // _prev_top_at_mark_start == top(),
- // _prev_marked_bytes == prev_marked_bytes
- }
- // If there is no mark in progress, we modified the _next variables
- // above needlessly, but harmlessly.
- if (_g1h->mark_in_progress()) {
- cur->note_start_of_marking(false);
- // _next_top_at_mark_start == top, _next_marked_bytes == 0
- // _next_marked_bytes == next_marked_bytes.
- }
- }
- cur = cur->next_in_collection_set();
- }
+ rsfp_task.work(0);
+ }
+
+ assert(check_cset_heap_region_claim_values(HeapRegion::ParEvacFailureClaimValue), "sanity");
+
+ // Reset the claim values in the regions in the collection set.
+ reset_cset_heap_region_claim_values();
+
+ assert(check_cset_heap_region_claim_values(HeapRegion::InitialClaimValue), "sanity");
assert(g1_policy()->assertMarkedBytesDataOK(), "Should be!");
// Now restore saved marks, if any.
@@ -4161,6 +4035,7 @@
markOop m = _preserved_marks_of_objs->at(i);
obj->set_mark(m);
}
+
// Delete the preserved marks growable arrays (allocated on the C heap).
delete _objs_with_preserved_marks;
delete _preserved_marks_of_objs;
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp Thu Jan 05 21:21:55 2012 -0800
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp Fri Dec 23 11:14:18 2011 -0800
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -1313,6 +1313,10 @@
// It resets all the region claim values to the default.
void reset_heap_region_claim_values();
+ // Resets the claim values of regions in the current
+ // collection set to the default.
+ void reset_cset_heap_region_claim_values();
+
#ifdef ASSERT
bool check_heap_region_claim_values(jint claim_value);
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1EvacFailure.hpp Fri Dec 23 11:14:18 2011 -0800
@@ -0,0 +1,228 @@
+/*
+ * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1EVACFAILURE_HPP
+#define SHARE_VM_GC_IMPLEMENTATION_G1_G1EVACFAILURE_HPP
+
+#include "gc_implementation/g1/concurrentMark.inline.hpp"
+#include "gc_implementation/g1/dirtyCardQueue.hpp"
+#include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
+#include "gc_implementation/g1/g1_globals.hpp"
+#include "gc_implementation/g1/g1OopClosures.inline.hpp"
+#include "gc_implementation/g1/heapRegion.hpp"
+#include "gc_implementation/g1/heapRegionRemSet.hpp"
+#include "utilities/workgroup.hpp"
+
+// Closures and tasks associated with any self-forwarding pointers
+// installed as a result of an evacuation failure.
+
+class UpdateRSetDeferred : public OopsInHeapRegionClosure {
+private:
+ G1CollectedHeap* _g1;
+ DirtyCardQueue *_dcq;
+ CardTableModRefBS* _ct_bs;
+
+public:
+ UpdateRSetDeferred(G1CollectedHeap* g1, DirtyCardQueue* dcq) :
+ _g1(g1), _ct_bs((CardTableModRefBS*)_g1->barrier_set()), _dcq(dcq) {}
+
+ virtual void do_oop(narrowOop* p) { do_oop_work(p); }
+ virtual void do_oop( oop* p) { do_oop_work(p); }
+ template <class T> void do_oop_work(T* p) {
+ assert(_from->is_in_reserved(p), "paranoia");
+ if (!_from->is_in_reserved(oopDesc::load_decode_heap_oop(p)) &&
+ !_from->is_survivor()) {
+ size_t card_index = _ct_bs->index_for(p);
+ if (_ct_bs->mark_card_deferred(card_index)) {
+ _dcq->enqueue((jbyte*)_ct_bs->byte_for_index(card_index));
+ }
+ }
+ }
+};
+
+class RemoveSelfForwardPtrObjClosure: public ObjectClosure {
+private:
+ G1CollectedHeap* _g1;
+ ConcurrentMark* _cm;
+ HeapRegion* _hr;
+ size_t _prev_marked_bytes;
+ size_t _next_marked_bytes;
+ OopsInHeapRegionClosure *_update_rset_cl;
+public:
+ RemoveSelfForwardPtrObjClosure(G1CollectedHeap* g1, ConcurrentMark* cm,
+ HeapRegion* hr,
+ OopsInHeapRegionClosure* update_rset_cl) :
+ _g1(g1), _cm(cm), _hr(hr),
+ _update_rset_cl(update_rset_cl),
+ _prev_marked_bytes(0), _next_marked_bytes(0) {}
+
+ size_t prev_marked_bytes() { return _prev_marked_bytes; }
+ size_t next_marked_bytes() { return _next_marked_bytes; }
+
+ // <original comment>
+ // The original idea here was to coalesce evacuated and dead objects.
+ // However that caused complications with the block offset table (BOT).
+ // In particular if there were two TLABs, one of them partially refined.
+ // |----- TLAB_1--------|----TLAB_2-~~~(partially refined part)~~~|
+ // The BOT entries of the unrefined part of TLAB_2 point to the start
+ // of TLAB_2. If the last object of the TLAB_1 and the first object
+ // of TLAB_2 are coalesced, then the cards of the unrefined part
+ // would point into middle of the filler object.
+ // The current approach is to not coalesce and leave the BOT contents intact.
+ // </original comment>
+ //
+ // We now reset the BOT when we start the object iteration over the
+ // region and refine its entries for every object we come across. So
+ // the above comment is not really relevant and we should be able
+ // to coalesce dead objects if we want to.
+ void do_object(oop obj) {
+ HeapWord* obj_addr = (HeapWord*) obj;
+ assert(_hr->is_in(obj_addr), "sanity");
+ size_t obj_size = obj->size();
+
+ _hr->update_bot_for_object(obj_addr, obj_size);
+
+ if (obj->is_forwarded() && obj->forwardee() == obj) {
+ // The object failed to move.
+ assert(!_g1->is_obj_dead(obj), "We should not be preserving dead objs.");
+ _cm->markPrev(obj);
+ assert(_cm->isPrevMarked(obj), "Should be marked!");
+ _prev_marked_bytes += (obj_size * HeapWordSize);
+ if (_g1->mark_in_progress() && !_g1->is_obj_ill(obj)) {
+ _cm->markAndGrayObjectIfNecessary(obj);
+ }
+ obj->set_mark(markOopDesc::prototype());
+
+ // While we were processing RSet buffers during the collection,
+ // we actually didn't scan any cards on the collection set,
+ // since we didn't want to update remembered sets with entries
+ // that point into the collection set, given that live objects
+ // from the collection set are about to move and such entries
+ // will be stale very soon.
+ // This change also dealt with a reliability issue which
+ // involved scanning a card in the collection set and coming
+ // across an array that was being chunked and looking malformed.
+ // The problem is that, if evacuation fails, we might have
+ // remembered set entries missing given that we skipped cards on
+ // the collection set. So, we'll recreate such entries now.
+
+ obj->oop_iterate(_update_rset_cl);
+ assert(_cm->isPrevMarked(obj), "Should be marked!");
+ } else {
+ // The object has been either evacuated or is dead. Fill it with a
+ // dummy object.
+ MemRegion mr((HeapWord*)obj, obj_size);
+ CollectedHeap::fill_with_object(mr);
+ _cm->clearRangeBothMaps(mr);
+ }
+ }
+};
+
+class RemoveSelfForwardPtrHRClosure: public HeapRegionClosure {
+ G1CollectedHeap* _g1h;
+ ConcurrentMark* _cm;
+ OopsInHeapRegionClosure *_update_rset_cl;
+
+public:
+ RemoveSelfForwardPtrHRClosure(G1CollectedHeap* g1h,
+ OopsInHeapRegionClosure* update_rset_cl) :
+ _g1h(g1h), _update_rset_cl(update_rset_cl),
+ _cm(_g1h->concurrent_mark()) { }
+
+ bool doHeapRegion(HeapRegion *hr) {
+ assert(!hr->isHumongous(), "sanity");
+ assert(hr->in_collection_set(), "bad CS");
+
+ if (hr->claimHeapRegion(HeapRegion::ParEvacFailureClaimValue)) {
+ if (hr->evacuation_failed()) {
+ RemoveSelfForwardPtrObjClosure rspc(_g1h, _cm, hr, _update_rset_cl);
+
+ // In the common case (i.e. when there is no evacuation
+ // failure) we make sure that the following is done when
+ // the region is freed so that it is "ready-to-go" when it's
+ // re-allocated. However, when evacuation failure happens, a
+ // region will remain in the heap and might ultimately be added
+ // to a CSet in the future. So we have to be careful here and
+ // make sure the region's RSet is ready for parallel iteration
+ // whenever this might be required in the future.
+ hr->rem_set()->reset_for_par_iteration();
+ hr->reset_bot();
+ _update_rset_cl->set_region(hr);
+ hr->object_iterate(&rspc);
+
+ // A number of manipulations to make the TAMS for this region
+ // be the current top, and the marked bytes be the ones observed
+ // in the iteration.
+ if (_cm->at_least_one_mark_complete()) {
+ // The comments below are the postconditions achieved by the
+ // calls. Note especially the last such condition, which says that
+ // the count of marked bytes has been properly restored.
+ hr->note_start_of_marking(false);
+ // _next_top_at_mark_start == top, _next_marked_bytes == 0
+ hr->add_to_marked_bytes(rspc.prev_marked_bytes());
+ // _next_marked_bytes == prev_marked_bytes.
+ hr->note_end_of_marking();
+ // _prev_top_at_mark_start == top(),
+ // _prev_marked_bytes == prev_marked_bytes
+ }
+ // If there is no mark in progress, we modified the _next variables
+ // above needlessly, but harmlessly.
+ if (_g1h->mark_in_progress()) {
+ hr->note_start_of_marking(false);
+ // _next_top_at_mark_start == top, _next_marked_bytes == 0
+ // _next_marked_bytes == next_marked_bytes.
+ }
+ }
+ }
+ return false;
+ }
+};
+
+class G1ParRemoveSelfForwardPtrsTask: public AbstractGangTask {
+protected:
+ G1CollectedHeap* _g1h;
+
+public:
+ G1ParRemoveSelfForwardPtrsTask(G1CollectedHeap* g1h) :
+ AbstractGangTask("G1 Remove Self-forwarding Pointers"),
+ _g1h(g1h) { }
+
+ void work(uint worker_id) {
+ UpdateRSetImmediate immediate_update(_g1h->g1_rem_set());
+ DirtyCardQueue dcq(&_g1h->dirty_card_queue_set());
+ UpdateRSetDeferred deferred_update(_g1h, &dcq);
+
+ OopsInHeapRegionClosure *update_rset_cl = &deferred_update;
+ if (!G1DeferredRSUpdate) {
+ update_rset_cl = &immediate_update;
+ }
+
+ RemoveSelfForwardPtrHRClosure rsfp_cl(_g1h, update_rset_cl);
+
+ HeapRegion* hr = _g1h->start_cset_region_for_worker(worker_id);
+ _g1h->collection_set_iterate_from(hr, &rsfp_cl);
+ }
+};
+
+#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1EVACFAILURE_HPP
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp Thu Jan 05 21:21:55 2012 -0800
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp Fri Dec 23 11:14:18 2011 -0800
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -373,7 +373,8 @@
ScrubRemSetClaimValue = 3,
ParVerifyClaimValue = 4,
RebuildRSClaimValue = 5,
- CompleteMarkCSetClaimValue = 6
+ CompleteMarkCSetClaimValue = 6,
+ ParEvacFailureClaimValue = 7
};
inline HeapWord* par_allocate_no_bot_updates(size_t word_size) {