--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/g1/g1IHOPControl.cpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,185 @@
+/*
+ * Copyright (c) 2015, 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/g1CollectedHeap.inline.hpp"
+#include "gc/g1/g1IHOPControl.hpp"
+#include "gc/g1/g1Predictions.hpp"
+#include "gc/shared/gcTrace.hpp"
+#include "logging/log.hpp"
+
+G1IHOPControl::G1IHOPControl(double initial_ihop_percent) :
+ _initial_ihop_percent(initial_ihop_percent),
+ _target_occupancy(0),
+ _last_allocated_bytes(0),
+ _last_allocation_time_s(0.0)
+{
+ assert(_initial_ihop_percent >= 0.0 && _initial_ihop_percent <= 100.0, "Initial IHOP value must be between 0 and 100 but is %.3f", initial_ihop_percent);
+}
+
+void G1IHOPControl::update_target_occupancy(size_t new_target_occupancy) {
+ log_debug(gc, ihop)("Target occupancy update: old: " SIZE_FORMAT "B, new: " SIZE_FORMAT "B",
+ _target_occupancy, new_target_occupancy);
+ _target_occupancy = new_target_occupancy;
+}
+
+void G1IHOPControl::update_allocation_info(double allocation_time_s, size_t allocated_bytes, size_t additional_buffer_size) {
+ assert(allocation_time_s >= 0.0, "Allocation time must be positive but is %.3f", allocation_time_s);
+
+ _last_allocation_time_s = allocation_time_s;
+ _last_allocated_bytes = allocated_bytes;
+}
+
+void G1IHOPControl::print() {
+ assert(_target_occupancy > 0, "Target occupancy still not updated yet.");
+ size_t cur_conc_mark_start_threshold = get_conc_mark_start_threshold();
+ log_debug(gc, ihop)("Basic information (value update), threshold: " SIZE_FORMAT "B (%1.2f), target occupancy: " SIZE_FORMAT "B, current occupancy: " SIZE_FORMAT "B, "
+ "recent allocation size: " SIZE_FORMAT "B, recent allocation duration: %1.2fms, recent old gen allocation rate: %1.2fB/s, recent marking phase length: %1.2fms",
+ cur_conc_mark_start_threshold,
+ cur_conc_mark_start_threshold * 100.0 / _target_occupancy,
+ _target_occupancy,
+ G1CollectedHeap::heap()->used(),
+ _last_allocated_bytes,
+ _last_allocation_time_s * 1000.0,
+ _last_allocation_time_s > 0.0 ? _last_allocated_bytes / _last_allocation_time_s : 0.0,
+ last_marking_length_s() * 1000.0);
+}
+
+void G1IHOPControl::send_trace_event(G1NewTracer* tracer) {
+ assert(_target_occupancy > 0, "Target occupancy still not updated yet.");
+ tracer->report_basic_ihop_statistics(get_conc_mark_start_threshold(),
+ _target_occupancy,
+ G1CollectedHeap::heap()->used(),
+ _last_allocated_bytes,
+ _last_allocation_time_s,
+ last_marking_length_s());
+}
+
+G1StaticIHOPControl::G1StaticIHOPControl(double ihop_percent) :
+ G1IHOPControl(ihop_percent),
+ _last_marking_length_s(0.0) {
+}
+
+G1AdaptiveIHOPControl::G1AdaptiveIHOPControl(double ihop_percent,
+ G1Predictions const* predictor,
+ size_t heap_reserve_percent,
+ size_t heap_waste_percent) :
+ G1IHOPControl(ihop_percent),
+ _predictor(predictor),
+ _marking_times_s(10, 0.95),
+ _allocation_rate_s(10, 0.95),
+ _last_unrestrained_young_size(0),
+ _heap_reserve_percent(heap_reserve_percent),
+ _heap_waste_percent(heap_waste_percent)
+{
+}
+
+size_t G1AdaptiveIHOPControl::actual_target_threshold() const {
+ guarantee(_target_occupancy > 0, "Target occupancy still not updated yet.");
+ // The actual target threshold takes the heap reserve and the expected waste in
+ // free space into account.
+ // _heap_reserve is that part of the total heap capacity that is reserved for
+ // eventual promotion failure.
+ // _heap_waste is the amount of space will never be reclaimed in any
+ // heap, so can not be used for allocation during marking and must always be
+ // considered.
+
+ double safe_total_heap_percentage = MIN2((double)(_heap_reserve_percent + _heap_waste_percent), 100.0);
+
+ return (size_t)MIN2(
+ G1CollectedHeap::heap()->max_capacity() * (100.0 - safe_total_heap_percentage) / 100.0,
+ _target_occupancy * (100.0 - _heap_waste_percent) / 100.0
+ );
+}
+
+bool G1AdaptiveIHOPControl::have_enough_data_for_prediction() const {
+ return ((size_t)_marking_times_s.num() >= G1AdaptiveIHOPNumInitialSamples) &&
+ ((size_t)_allocation_rate_s.num() >= G1AdaptiveIHOPNumInitialSamples);
+}
+
+size_t G1AdaptiveIHOPControl::get_conc_mark_start_threshold() {
+ if (have_enough_data_for_prediction()) {
+ double pred_marking_time = _predictor->get_new_prediction(&_marking_times_s);
+ double pred_promotion_rate = _predictor->get_new_prediction(&_allocation_rate_s);
+ size_t pred_promotion_size = (size_t)(pred_marking_time * pred_promotion_rate);
+
+ size_t predicted_needed_bytes_during_marking =
+ pred_promotion_size +
+ // In reality we would need the maximum size of the young gen during
+ // marking. This is a conservative estimate.
+ _last_unrestrained_young_size;
+
+ size_t internal_threshold = actual_target_threshold();
+ size_t predicted_initiating_threshold = predicted_needed_bytes_during_marking < internal_threshold ?
+ internal_threshold - predicted_needed_bytes_during_marking :
+ 0;
+ return predicted_initiating_threshold;
+ } else {
+ // Use the initial value.
+ return (size_t)(_initial_ihop_percent * _target_occupancy / 100.0);
+ }
+}
+
+void G1AdaptiveIHOPControl::update_allocation_info(double allocation_time_s,
+ size_t allocated_bytes,
+ size_t additional_buffer_size) {
+ G1IHOPControl::update_allocation_info(allocation_time_s, allocated_bytes, additional_buffer_size);
+
+ double allocation_rate = (double) allocated_bytes / allocation_time_s;
+ _allocation_rate_s.add(allocation_rate);
+
+ _last_unrestrained_young_size = additional_buffer_size;
+}
+
+void G1AdaptiveIHOPControl::update_marking_length(double marking_length_s) {
+ assert(marking_length_s >= 0.0, "Marking length must be larger than zero but is %.3f", marking_length_s);
+ _marking_times_s.add(marking_length_s);
+}
+
+void G1AdaptiveIHOPControl::print() {
+ G1IHOPControl::print();
+ size_t actual_target = actual_target_threshold();
+ log_debug(gc, ihop)("Adaptive IHOP information (value update), threshold: " SIZE_FORMAT "B (%1.2f), internal target occupancy: " SIZE_FORMAT "B, "
+ "occupancy: " SIZE_FORMAT "B, additional buffer size: " SIZE_FORMAT "B, predicted old gen allocation rate: %1.2fB/s, "
+ "predicted marking phase length: %1.2fms, prediction active: %s",
+ get_conc_mark_start_threshold(),
+ percent_of(get_conc_mark_start_threshold(), actual_target),
+ actual_target,
+ G1CollectedHeap::heap()->used(),
+ _last_unrestrained_young_size,
+ _predictor->get_new_prediction(&_allocation_rate_s),
+ _predictor->get_new_prediction(&_marking_times_s) * 1000.0,
+ have_enough_data_for_prediction() ? "true" : "false");
+}
+
+void G1AdaptiveIHOPControl::send_trace_event(G1NewTracer* tracer) {
+ G1IHOPControl::send_trace_event(tracer);
+ tracer->report_adaptive_ihop_statistics(get_conc_mark_start_threshold(),
+ actual_target_threshold(),
+ G1CollectedHeap::heap()->used(),
+ _last_unrestrained_young_size,
+ _predictor->get_new_prediction(&_allocation_rate_s),
+ _predictor->get_new_prediction(&_marking_times_s),
+ have_enough_data_for_prediction());
+}