6923991: G1: improve scalability of RSet scanning
Summary: Implemented block-based work stealing. Moved copying during the rset scanning phase to the main copying phase. Made the size of rset table depend on the region size.
Reviewed-by: apetrusenko, tonyp
/*
* Copyright 2001-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
*/
/*
* This really ought to be an inline function, but apparently the C++
* compiler sometimes sees fit to ignore inline declarations. Sigh.
*/
// This must a ifdef'ed because the counting it controls is in a
// perf-critical inner loop.
#define FILTERINTOCSCLOSURE_DOHISTOGRAMCOUNT 0
template <class T> inline void FilterIntoCSClosure::do_oop_nv(T* p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop) &&
_g1->obj_in_cs(oopDesc::decode_heap_oop_not_null(heap_oop))) {
_oc->do_oop(p);
#if FILTERINTOCSCLOSURE_DOHISTOGRAMCOUNT
_dcto_cl->incr_count();
#endif
}
}
#define FILTEROUTOFREGIONCLOSURE_DOHISTOGRAMCOUNT 0
template <class T> inline void FilterOutOfRegionClosure::do_oop_nv(T* p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop)) {
HeapWord* obj_hw = (HeapWord*)oopDesc::decode_heap_oop_not_null(heap_oop);
if (obj_hw < _r_bottom || obj_hw >= _r_end) {
_oc->do_oop(p);
#if FILTEROUTOFREGIONCLOSURE_DOHISTOGRAMCOUNT
_out_of_region++;
#endif
}
}
}
template <class T> inline void FilterInHeapRegionAndIntoCSClosure::do_oop_nv(T* p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop) &&
_g1->obj_in_cs(oopDesc::decode_heap_oop_not_null(heap_oop)))
_oc->do_oop(p);
}
template <class T> inline void FilterAndMarkInHeapRegionAndIntoCSClosure::do_oop_nv(T* p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop)) {
oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
HeapRegion* hr = _g1->heap_region_containing((HeapWord*) obj);
if (hr != NULL) {
if (hr->in_collection_set())
_oc->do_oop(p);
else if (!hr->is_young())
_cm->grayRoot(obj);
}
}
}
// This closure is applied to the fields of the objects that have just been copied.
template <class T> inline void G1ParScanClosure::do_oop_nv(T* p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop)) {
oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
if (_g1->in_cset_fast_test(obj)) {
// We're not going to even bother checking whether the object is
// already forwarded or not, as this usually causes an immediate
// stall. We'll try to prefetch the object (for write, given that
// we might need to install the forwarding reference) and we'll
// get back to it when pop it from the queue
Prefetch::write(obj->mark_addr(), 0);
Prefetch::read(obj->mark_addr(), (HeapWordSize*2));
// slightly paranoid test; I'm trying to catch potential
// problems before we go into push_on_queue to know where the
// problem is coming from
assert(obj == oopDesc::load_decode_heap_oop(p),
"p should still be pointing to obj");
_par_scan_state->push_on_queue(p);
} else {
_par_scan_state->update_rs(_from, p, _par_scan_state->queue_num());
}
}
}
template <class T> inline void G1ParPushHeapRSClosure::do_oop_nv(T* p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop)) {
oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
if (_g1->in_cset_fast_test(obj)) {
Prefetch::write(obj->mark_addr(), 0);
Prefetch::read(obj->mark_addr(), (HeapWordSize*2));
_par_scan_state->push_on_queue(p);
}
}
}