jdk/src/hotspot/share/gc/g1/g1ConcurrentCycleTracker.cpp
Ivan Walulya 85db081db4 8379846: G1: IHOP Allocation rate calculation too sensitive to outliers causing endless concurrent cycles
Co-authored-by: Thomas Schatzl <tschatzl@openjdk.org>
Reviewed-by: tschatzl, aboldtch
2026-06-03 14:04:11 +00:00

132 lines
4.4 KiB
C++

/*
* Copyright (c) 2026, 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
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#include "gc/g1/g1ConcurrentCycleTracker.hpp"
#include "gc/g1/g1OldGenAllocationTracker.hpp"
#include "utilities/checkedCast.hpp"
#include "utilities/debug.hpp"
void G1ConcurrentCycleTracker::reset() {
_state = CycleState::Inactive;
_total_pause_time_s = 0.0;
_cycle_start_time_s = 0.0;
_cycle_end_time_s = 0.0;
_humongous_bytes_at_start = 0;
_non_humongous_allocated_bytes = 0;
_peak_extra_humongous_occupancy_bytes = 0;
}
void G1ConcurrentCycleTracker::update_allocation_stats(G1AllocationIntervalStats interval_stats) {
if (!is_active()) {
return;
}
_non_humongous_allocated_bytes += interval_stats._non_humongous_allocated_bytes;
intptr_t delta_before = checked_cast<intptr_t>(interval_stats._total_humongous_before_bytes) -
checked_cast<intptr_t>(_humongous_bytes_at_start);
intptr_t delta_after = delta_before +
checked_cast<intptr_t>(interval_stats._humongous_allocated_bytes);
if (delta_after > 0) {
_peak_extra_humongous_occupancy_bytes = MAX2(_peak_extra_humongous_occupancy_bytes, checked_cast<size_t>(delta_after));
}
}
G1ConcurrentCycleTracker::G1ConcurrentCycleTracker()
: _state(CycleState::Inactive),
_cycle_start_time_s(0.0),
_cycle_end_time_s(0.0),
_total_pause_time_s(0.0),
_humongous_bytes_at_start(0),
_non_humongous_allocated_bytes(0),
_peak_extra_humongous_occupancy_bytes(0)
{ }
void G1ConcurrentCycleTracker::record_cycle_start(double cycle_start_time_s, size_t humongous_bytes_after_pause) {
assert(_state == CycleState::Inactive, "Concurrent start out of order.");
_cycle_start_time_s = cycle_start_time_s;
_humongous_bytes_at_start = humongous_bytes_after_pause;
_state = CycleState::Active;
}
void G1ConcurrentCycleTracker::record_allocation_interval(Pause pause_type,
bool is_periodic_gc,
double pause_start_time_s,
double pause_end_time_s,
G1AllocationIntervalStats interval_stats) {
if (is_periodic_gc || pause_type == Pause::Full || pause_type == Pause::ConcurrentStartUndo) {
reset();
return;
}
if (pause_type == Pause::ConcurrentStartFull) {
record_cycle_start(pause_end_time_s, interval_stats._total_humongous_after_bytes);
return;
}
if (!is_active()) {
return;
}
update_allocation_stats(interval_stats);
if (pause_type == Pause::Mixed) {
complete_cycle(pause_start_time_s);
return;
}
assert(pause_type == Pause::Normal ||
pause_type == Pause::PrepareMixed ||
pause_type == Pause::Remark ||
pause_type == Pause::Cleanup,
"Unhandled pause type");
add_pause(pause_end_time_s - pause_start_time_s);
}
void G1ConcurrentCycleTracker::complete_cycle(double cycle_end_time_s) {
precond(is_active());
_cycle_end_time_s = cycle_end_time_s;
_state = CycleState::Complete;
}
G1ConcurrentCycleStats G1ConcurrentCycleTracker::get_and_reset_cycle_stats() {
precond(has_completed_cycle());
double cycle_duration = (_cycle_end_time_s - _cycle_start_time_s - _total_pause_time_s);
G1ConcurrentCycleStats stats{
cycle_duration,
_non_humongous_allocated_bytes,
_peak_extra_humongous_occupancy_bytes
};
reset();
return stats;
}