9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "memory/allocation.inline.hpp"
27 #include "gc/g1/g1EvacStats.hpp"
28 #include "gc/shared/gcId.hpp"
29 #include "trace/tracing.hpp"
30
31 void G1EvacStats::adjust_desired_plab_sz() {
32 if (PrintPLAB) {
33 gclog_or_tty->print(" (allocated = " SIZE_FORMAT " wasted = " SIZE_FORMAT " "
34 "unused = " SIZE_FORMAT " used = " SIZE_FORMAT " "
35 "undo_waste = " SIZE_FORMAT " region_end_waste = " SIZE_FORMAT " "
36 "regions filled = %u direct_allocated = " SIZE_FORMAT " "
37 "failure_used = " SIZE_FORMAT " failure_waste = " SIZE_FORMAT ") ",
38 _allocated, _wasted, _unused, used(), _undo_wasted, _region_end_waste,
39 _regions_filled, _direct_allocated, _failure_used, _failure_waste);
40 }
41
42 if (ResizePLAB) {
43
44 assert(is_object_aligned(max_size()) && min_size() <= max_size(),
45 "PLAB clipping computation may be incorrect");
46
47 if (_allocated == 0) {
48 assert((_unused == 0),
49 "Inconsistency in PLAB stats: "
50 "_allocated: " SIZE_FORMAT ", "
51 "_wasted: " SIZE_FORMAT ", "
52 "_region_end_waste: " SIZE_FORMAT ", "
53 "_unused: " SIZE_FORMAT ", "
54 "_used : " SIZE_FORMAT,
55 _allocated, _wasted, _region_end_waste, _unused, used());
56 _allocated = 1;
57 }
58 // The size of the PLAB caps the amount of space that can be wasted at the
59 // end of the collection. In the worst case the last PLAB could be completely
60 // empty.
61 // This allows us to calculate the new PLAB size to achieve the
62 // TargetPLABWastePct given the latest memory usage and that the last buffer
63 // will be G1LastPLABAverageOccupancy full.
87 //
88 // We need to cover overflow when calculating the amount of space actually used
89 // by objects in PLABs when subtracting the region end waste.
90 // Region end waste may be higher than actual allocation. This may occur if many
91 // threads do not allocate anything but a few rather large objects. In this
92 // degenerate case the PLAB size would simply quickly tend to minimum PLAB size,
93 // which is an okay reaction.
94 size_t const used_for_waste_calculation = used() > _region_end_waste ? used() - _region_end_waste : 0;
95
96 size_t const total_waste_allowed = used_for_waste_calculation * TargetPLABWastePct;
97 size_t const cur_plab_sz = (size_t)((double)total_waste_allowed / G1LastPLABAverageOccupancy);
98 // Take historical weighted average
99 _filter.sample(cur_plab_sz);
100 // Clip from above and below, and align to object boundary
101 size_t plab_sz;
102 plab_sz = MAX2(min_size(), (size_t)_filter.average());
103 plab_sz = MIN2(max_size(), plab_sz);
104 plab_sz = align_object_size(plab_sz);
105 // Latch the result
106 _desired_net_plab_sz = plab_sz;
107 if (PrintPLAB) {
108 gclog_or_tty->print(" (plab_sz = " SIZE_FORMAT " desired_plab_sz = " SIZE_FORMAT ") ", cur_plab_sz, plab_sz);
109 }
110 }
111 if (PrintPLAB) {
112 gclog_or_tty->cr();
113 }
114 // Clear accumulators for next round.
115 reset();
116 }
117
118 G1EvacStats::~G1EvacStats() { }
|
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "memory/allocation.inline.hpp"
27 #include "gc/g1/g1EvacStats.hpp"
28 #include "gc/shared/gcId.hpp"
29 #include "logging/log.hpp"
30 #include "trace/tracing.hpp"
31
32 void G1EvacStats::adjust_desired_plab_sz() {
33 if (!ResizePLAB) {
34 log_debug(gc, plab)(" (allocated = " SIZE_FORMAT " wasted = " SIZE_FORMAT " "
35 "unused = " SIZE_FORMAT " used = " SIZE_FORMAT " "
36 "undo_waste = " SIZE_FORMAT " region_end_waste = " SIZE_FORMAT " "
37 "regions filled = %u direct_allocated = " SIZE_FORMAT " "
38 "failure_used = " SIZE_FORMAT " failure_waste = " SIZE_FORMAT ") ",
39 _allocated, _wasted, _unused, used(), _undo_wasted, _region_end_waste,
40 _regions_filled, _direct_allocated, _failure_used, _failure_waste);
41 // Clear accumulators for next round.
42 reset();
43 return;
44 }
45
46 assert(is_object_aligned(max_size()) && min_size() <= max_size(),
47 "PLAB clipping computation may be incorrect");
48
49 if (_allocated == 0) {
50 assert((_unused == 0),
51 "Inconsistency in PLAB stats: "
52 "_allocated: " SIZE_FORMAT ", "
53 "_wasted: " SIZE_FORMAT ", "
54 "_region_end_waste: " SIZE_FORMAT ", "
55 "_unused: " SIZE_FORMAT ", "
56 "_used : " SIZE_FORMAT,
57 _allocated, _wasted, _region_end_waste, _unused, used());
58 _allocated = 1;
59 }
60 // The size of the PLAB caps the amount of space that can be wasted at the
61 // end of the collection. In the worst case the last PLAB could be completely
62 // empty.
63 // This allows us to calculate the new PLAB size to achieve the
64 // TargetPLABWastePct given the latest memory usage and that the last buffer
65 // will be G1LastPLABAverageOccupancy full.
89 //
90 // We need to cover overflow when calculating the amount of space actually used
91 // by objects in PLABs when subtracting the region end waste.
92 // Region end waste may be higher than actual allocation. This may occur if many
93 // threads do not allocate anything but a few rather large objects. In this
94 // degenerate case the PLAB size would simply quickly tend to minimum PLAB size,
95 // which is an okay reaction.
96 size_t const used_for_waste_calculation = used() > _region_end_waste ? used() - _region_end_waste : 0;
97
98 size_t const total_waste_allowed = used_for_waste_calculation * TargetPLABWastePct;
99 size_t const cur_plab_sz = (size_t)((double)total_waste_allowed / G1LastPLABAverageOccupancy);
100 // Take historical weighted average
101 _filter.sample(cur_plab_sz);
102 // Clip from above and below, and align to object boundary
103 size_t plab_sz;
104 plab_sz = MAX2(min_size(), (size_t)_filter.average());
105 plab_sz = MIN2(max_size(), plab_sz);
106 plab_sz = align_object_size(plab_sz);
107 // Latch the result
108 _desired_net_plab_sz = plab_sz;
109
110 log_debug(gc, plab)(" (allocated = " SIZE_FORMAT " wasted = " SIZE_FORMAT " "
111 "unused = " SIZE_FORMAT " used = " SIZE_FORMAT " "
112 "undo_waste = " SIZE_FORMAT " region_end_waste = " SIZE_FORMAT " "
113 "regions filled = %u direct_allocated = " SIZE_FORMAT " "
114 "failure_used = " SIZE_FORMAT " failure_waste = " SIZE_FORMAT ") "
115 " (plab_sz = " SIZE_FORMAT " desired_plab_sz = " SIZE_FORMAT ")",
116 _allocated, _wasted, _unused, used(), _undo_wasted, _region_end_waste,
117 _regions_filled, _direct_allocated, _failure_used, _failure_waste,
118 cur_plab_sz, plab_sz);
119
120 // Clear accumulators for next round.
121 reset();
122 }
123
124 G1EvacStats::~G1EvacStats() { }
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