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/*
* Copyright (c) 2015, 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/g1EvacStats.hpp"
#include "gc/shared/gcId.hpp"
#include "trace/tracing.hpp"
void G1EvacStats::adjust_desired_plab_sz() {
if (PrintPLAB) {
gclog_or_tty->print(" (allocated = " SIZE_FORMAT " wasted = " SIZE_FORMAT " "
"unused = " SIZE_FORMAT " used = " SIZE_FORMAT " "
"undo_waste = " SIZE_FORMAT " region_end_waste = " SIZE_FORMAT " "
"regions filled = %u direct_allocated = " SIZE_FORMAT " "
"failure_used = " SIZE_FORMAT " failure_waste = " SIZE_FORMAT ") ",
_allocated, _wasted, _unused, used(), _undo_wasted, _region_end_waste,
_regions_filled, _direct_allocated, _failure_used, _failure_waste);
}
if (ResizePLAB) {
assert(is_object_aligned(max_size()) && min_size() <= max_size(),
"PLAB clipping computation may be incorrect");
if (_allocated == 0) {
assert((_unused == 0),
err_msg("Inconsistency in PLAB stats: "
"_allocated: "SIZE_FORMAT", "
"_wasted: "SIZE_FORMAT", "
"_region_end_waste: "SIZE_FORMAT", "
"_unused: "SIZE_FORMAT", "
"_used : "SIZE_FORMAT,
_allocated, _wasted, _region_end_waste, _unused, used()));
_allocated = 1;
}
// We account region end waste fully to PLAB allocation. This is not completely fair,
// but is a conservative assumption because PLABs may be sized flexibly while we
// cannot adjust direct allocations.
// In some cases, wasted_frac may become > 1 but that just reflects the problem
// with region_end_waste.
double wasted_frac = (double)(_unused + _wasted + _region_end_waste) / (double)_allocated;
size_t target_refills = (size_t)((wasted_frac * TargetSurvivorRatio) / TargetPLABWastePct);
if (target_refills == 0) {
target_refills = 1;
}
size_t cur_plab_sz = used() / target_refills;
// Take historical weighted average
_filter.sample(cur_plab_sz);
// Clip from above and below, and align to object boundary
size_t plab_sz;
plab_sz = MAX2(min_size(), (size_t)_filter.average());
plab_sz = MIN2(max_size(), plab_sz);
plab_sz = align_object_size(plab_sz);
// Latch the result
_desired_net_plab_sz = plab_sz;
if (PrintPLAB) {
gclog_or_tty->print_cr(" (plab_sz = " SIZE_FORMAT " desired_plab_sz = " SIZE_FORMAT ") ", cur_plab_sz, plab_sz);
}
}
// Clear accumulators for next round.
reset();
}