--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/g1/g1Analytics.cpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,332 @@
+/*
+ * Copyright (c) 2016, 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.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "gc/g1/g1Analytics.hpp"
+#include "gc/g1/g1Predictions.hpp"
+#include "runtime/os.hpp"
+#include "utilities/debug.hpp"
+#include "utilities/numberSeq.hpp"
+
+// Different defaults for different number of GC threads
+// They were chosen by running GCOld and SPECjbb on debris with different
+// numbers of GC threads and choosing them based on the results
+
+// all the same
+static double rs_length_diff_defaults[] = {
+ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0
+};
+
+static double cost_per_card_ms_defaults[] = {
+ 0.01, 0.005, 0.005, 0.003, 0.003, 0.002, 0.002, 0.0015
+};
+
+// all the same
+static double young_cards_per_entry_ratio_defaults[] = {
+ 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
+};
+
+static double cost_per_entry_ms_defaults[] = {
+ 0.015, 0.01, 0.01, 0.008, 0.008, 0.0055, 0.0055, 0.005
+};
+
+static double cost_per_byte_ms_defaults[] = {
+ 0.00006, 0.00003, 0.00003, 0.000015, 0.000015, 0.00001, 0.00001, 0.000009
+};
+
+// these should be pretty consistent
+static double constant_other_time_ms_defaults[] = {
+ 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0
+};
+
+
+static double young_other_cost_per_region_ms_defaults[] = {
+ 0.3, 0.2, 0.2, 0.15, 0.15, 0.12, 0.12, 0.1
+};
+
+static double non_young_other_cost_per_region_ms_defaults[] = {
+ 1.0, 0.7, 0.7, 0.5, 0.5, 0.42, 0.42, 0.30
+};
+
+G1Analytics::G1Analytics(const G1Predictions* predictor) :
+ _predictor(predictor),
+ _recent_gc_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
+ _concurrent_mark_remark_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
+ _concurrent_mark_cleanup_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
+ _alloc_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
+ _prev_collection_pause_end_ms(0.0),
+ _rs_length_diff_seq(new TruncatedSeq(TruncatedSeqLength)),
+ _cost_per_card_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
+ _cost_scan_hcc_seq(new TruncatedSeq(TruncatedSeqLength)),
+ _young_cards_per_entry_ratio_seq(new TruncatedSeq(TruncatedSeqLength)),
+ _mixed_cards_per_entry_ratio_seq(new TruncatedSeq(TruncatedSeqLength)),
+ _cost_per_entry_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
+ _mixed_cost_per_entry_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
+ _cost_per_byte_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
+ _cost_per_byte_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)),
+ _constant_other_time_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
+ _young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
+ _non_young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
+ _pending_cards_seq(new TruncatedSeq(TruncatedSeqLength)),
+ _rs_lengths_seq(new TruncatedSeq(TruncatedSeqLength)),
+ _recent_prev_end_times_for_all_gcs_sec(new TruncatedSeq(NumPrevPausesForHeuristics)) {
+
+ // Seed sequences with initial values.
+ _recent_prev_end_times_for_all_gcs_sec->add(os::elapsedTime());
+ _prev_collection_pause_end_ms = os::elapsedTime() * 1000.0;
+
+ int index = MIN2(ParallelGCThreads - 1, 7u);
+
+ _rs_length_diff_seq->add(rs_length_diff_defaults[index]);
+ _cost_per_card_ms_seq->add(cost_per_card_ms_defaults[index]);
+ _cost_scan_hcc_seq->add(0.0);
+ _young_cards_per_entry_ratio_seq->add(young_cards_per_entry_ratio_defaults[index]);
+ _cost_per_entry_ms_seq->add(cost_per_entry_ms_defaults[index]);
+ _cost_per_byte_ms_seq->add(cost_per_byte_ms_defaults[index]);
+ _constant_other_time_ms_seq->add(constant_other_time_ms_defaults[index]);
+ _young_other_cost_per_region_ms_seq->add(young_other_cost_per_region_ms_defaults[index]);
+ _non_young_other_cost_per_region_ms_seq->add(non_young_other_cost_per_region_ms_defaults[index]);
+
+ // start conservatively (around 50ms is about right)
+ _concurrent_mark_remark_times_ms->add(0.05);
+ _concurrent_mark_cleanup_times_ms->add(0.20);
+}
+
+double G1Analytics::get_new_prediction(TruncatedSeq const* seq) const {
+ return _predictor->get_new_prediction(seq);
+}
+
+size_t G1Analytics::get_new_size_prediction(TruncatedSeq const* seq) const {
+ return (size_t)get_new_prediction(seq);
+}
+
+int G1Analytics::num_alloc_rate_ms() const {
+ return _alloc_rate_ms_seq->num();
+}
+
+void G1Analytics::report_concurrent_mark_remark_times_ms(double ms) {
+ _concurrent_mark_remark_times_ms->add(ms);
+}
+
+void G1Analytics::report_alloc_rate_ms(double alloc_rate) {
+ _alloc_rate_ms_seq->add(alloc_rate);
+}
+
+void G1Analytics::compute_pause_time_ratio(double interval_ms, double pause_time_ms) {
+ _recent_avg_pause_time_ratio = _recent_gc_times_ms->sum() / interval_ms;
+ if (_recent_avg_pause_time_ratio < 0.0 ||
+ (_recent_avg_pause_time_ratio - 1.0 > 0.0)) {
+ // Clip ratio between 0.0 and 1.0, and continue. This will be fixed in
+ // CR 6902692 by redoing the manner in which the ratio is incrementally computed.
+ if (_recent_avg_pause_time_ratio < 0.0) {
+ _recent_avg_pause_time_ratio = 0.0;
+ } else {
+ assert(_recent_avg_pause_time_ratio - 1.0 > 0.0, "Ctl-point invariant");
+ _recent_avg_pause_time_ratio = 1.0;
+ }
+ }
+
+ // Compute the ratio of just this last pause time to the entire time range stored
+ // in the vectors. Comparing this pause to the entire range, rather than only the
+ // most recent interval, has the effect of smoothing over a possible transient 'burst'
+ // of more frequent pauses that don't really reflect a change in heap occupancy.
+ // This reduces the likelihood of a needless heap expansion being triggered.
+ _last_pause_time_ratio =
+ (pause_time_ms * _recent_prev_end_times_for_all_gcs_sec->num()) / interval_ms;
+}
+
+void G1Analytics::report_cost_per_card_ms(double cost_per_card_ms) {
+ _cost_per_card_ms_seq->add(cost_per_card_ms);
+}
+
+void G1Analytics::report_cost_scan_hcc(double cost_scan_hcc) {
+ _cost_scan_hcc_seq->add(cost_scan_hcc);
+}
+
+void G1Analytics::report_cost_per_entry_ms(double cost_per_entry_ms, bool last_gc_was_young) {
+ if (last_gc_was_young) {
+ _cost_per_entry_ms_seq->add(cost_per_entry_ms);
+ } else {
+ _mixed_cost_per_entry_ms_seq->add(cost_per_entry_ms);
+ }
+}
+
+void G1Analytics::report_cards_per_entry_ratio(double cards_per_entry_ratio, bool last_gc_was_young) {
+ if (last_gc_was_young) {
+ _young_cards_per_entry_ratio_seq->add(cards_per_entry_ratio);
+ } else {
+ _mixed_cards_per_entry_ratio_seq->add(cards_per_entry_ratio);
+ }
+}
+
+void G1Analytics::report_rs_length_diff(double rs_length_diff) {
+ _rs_length_diff_seq->add(rs_length_diff);
+}
+
+void G1Analytics::report_cost_per_byte_ms(double cost_per_byte_ms, bool in_marking_window) {
+ if (in_marking_window) {
+ _cost_per_byte_ms_during_cm_seq->add(cost_per_byte_ms);
+ } else {
+ _cost_per_byte_ms_seq->add(cost_per_byte_ms);
+ }
+}
+
+void G1Analytics::report_young_other_cost_per_region_ms(double other_cost_per_region_ms) {
+ _young_other_cost_per_region_ms_seq->add(other_cost_per_region_ms);
+}
+
+void G1Analytics::report_non_young_other_cost_per_region_ms(double other_cost_per_region_ms) {
+ _non_young_other_cost_per_region_ms_seq->add(other_cost_per_region_ms);
+}
+
+void G1Analytics::report_constant_other_time_ms(double constant_other_time_ms) {
+ _constant_other_time_ms_seq->add(constant_other_time_ms);
+}
+
+void G1Analytics::report_pending_cards(double pending_cards) {
+ _pending_cards_seq->add(pending_cards);
+}
+
+void G1Analytics::report_rs_lengths(double rs_lengths) {
+ _rs_lengths_seq->add(rs_lengths);
+}
+
+size_t G1Analytics::predict_rs_length_diff() const {
+ return get_new_size_prediction(_rs_length_diff_seq);
+}
+
+double G1Analytics::predict_alloc_rate_ms() const {
+ return get_new_prediction(_alloc_rate_ms_seq);
+}
+
+double G1Analytics::predict_cost_per_card_ms() const {
+ return get_new_prediction(_cost_per_card_ms_seq);
+}
+
+double G1Analytics::predict_scan_hcc_ms() const {
+ return get_new_prediction(_cost_scan_hcc_seq);
+}
+
+double G1Analytics::predict_rs_update_time_ms(size_t pending_cards) const {
+ return pending_cards * predict_cost_per_card_ms() + predict_scan_hcc_ms();
+}
+
+double G1Analytics::predict_young_cards_per_entry_ratio() const {
+ return get_new_prediction(_young_cards_per_entry_ratio_seq);
+}
+
+double G1Analytics::predict_mixed_cards_per_entry_ratio() const {
+ if (_mixed_cards_per_entry_ratio_seq->num() < 2) {
+ return predict_young_cards_per_entry_ratio();
+ } else {
+ return get_new_prediction(_mixed_cards_per_entry_ratio_seq);
+ }
+}
+
+size_t G1Analytics::predict_card_num(size_t rs_length, bool gcs_are_young) const {
+ if (gcs_are_young) {
+ return (size_t) (rs_length * predict_young_cards_per_entry_ratio());
+ } else {
+ return (size_t) (rs_length * predict_mixed_cards_per_entry_ratio());
+ }
+}
+
+double G1Analytics::predict_rs_scan_time_ms(size_t card_num, bool gcs_are_young) const {
+ if (gcs_are_young) {
+ return card_num * get_new_prediction(_cost_per_entry_ms_seq);
+ } else {
+ return predict_mixed_rs_scan_time_ms(card_num);
+ }
+}
+
+double G1Analytics::predict_mixed_rs_scan_time_ms(size_t card_num) const {
+ if (_mixed_cost_per_entry_ms_seq->num() < 3) {
+ return card_num * get_new_prediction(_cost_per_entry_ms_seq);
+ } else {
+ return card_num * get_new_prediction(_mixed_cost_per_entry_ms_seq);
+ }
+}
+
+double G1Analytics::predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) const {
+ if (_cost_per_byte_ms_during_cm_seq->num() < 3) {
+ return (1.1 * bytes_to_copy) * get_new_prediction(_cost_per_byte_ms_seq);
+ } else {
+ return bytes_to_copy * get_new_prediction(_cost_per_byte_ms_during_cm_seq);
+ }
+}
+
+double G1Analytics::predict_object_copy_time_ms(size_t bytes_to_copy, bool during_concurrent_mark) const {
+ if (during_concurrent_mark) {
+ return predict_object_copy_time_ms_during_cm(bytes_to_copy);
+ } else {
+ return bytes_to_copy * get_new_prediction(_cost_per_byte_ms_seq);
+ }
+}
+
+double G1Analytics::predict_cost_per_byte_ms() const {
+ return get_new_prediction(_cost_per_byte_ms_seq);
+}
+
+double G1Analytics::predict_constant_other_time_ms() const {
+ return get_new_prediction(_constant_other_time_ms_seq);
+}
+
+double G1Analytics::predict_young_other_time_ms(size_t young_num) const {
+ return young_num * get_new_prediction(_young_other_cost_per_region_ms_seq);
+}
+
+double G1Analytics::predict_non_young_other_time_ms(size_t non_young_num) const {
+ return non_young_num * get_new_prediction(_non_young_other_cost_per_region_ms_seq);
+}
+
+double G1Analytics::predict_remark_time_ms() const {
+ return get_new_prediction(_concurrent_mark_remark_times_ms);
+}
+
+double G1Analytics::predict_cleanup_time_ms() const {
+ return get_new_prediction(_concurrent_mark_cleanup_times_ms);
+}
+
+size_t G1Analytics::predict_rs_lengths() const {
+ return get_new_size_prediction(_rs_lengths_seq);
+}
+
+size_t G1Analytics::predict_pending_cards() const {
+ return get_new_size_prediction(_pending_cards_seq);
+}
+
+double G1Analytics::last_known_gc_end_time_sec() const {
+ return _recent_prev_end_times_for_all_gcs_sec->oldest();
+}
+
+void G1Analytics::update_recent_gc_times(double end_time_sec,
+ double pause_time_ms) {
+ _recent_gc_times_ms->add(pause_time_ms);
+ _recent_prev_end_times_for_all_gcs_sec->add(end_time_sec);
+ _prev_collection_pause_end_ms = end_time_sec * 1000.0;
+}
+
+void G1Analytics::report_concurrent_mark_cleanup_times_ms(double ms) {
+ _concurrent_mark_cleanup_times_ms->add(ms);
+}