1 /* 2 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 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 "gc/g1/g1EvacStats.hpp" 27 #include "gc/shared/gcId.hpp" 28 #include "trace/tracing.hpp" 29 30 void G1EvacStats::adjust_desired_plab_sz() { 31 if (PrintPLAB) { 32 gclog_or_tty->print(" (allocated = " SIZE_FORMAT " wasted = " SIZE_FORMAT " " 33 "unused = " SIZE_FORMAT " used = " SIZE_FORMAT " " 34 "undo_waste = " SIZE_FORMAT " region_end_waste = " SIZE_FORMAT " " 35 "regions filled = %u direct_allocated = " SIZE_FORMAT " " 36 "failure_used = " SIZE_FORMAT " failure_waste = " SIZE_FORMAT ") ", 37 _allocated, _wasted, _unused, used(), _undo_wasted, _region_end_waste, 38 _regions_filled, _direct_allocated, _failure_used, _failure_waste); 39 } 40 41 if (ResizePLAB) { 42 43 assert(is_object_aligned(max_size()) && min_size() <= max_size(), 44 "PLAB clipping computation may be incorrect"); 45 46 if (_allocated == 0) { 47 assert((_unused == 0), 48 err_msg("Inconsistency in PLAB stats: " 49 "_allocated: "SIZE_FORMAT", " 50 "_wasted: "SIZE_FORMAT", " 51 "_region_end_waste: "SIZE_FORMAT", " 52 "_unused: "SIZE_FORMAT", " 53 "_used : "SIZE_FORMAT, 54 _allocated, _wasted, _region_end_waste, _unused, used())); 55 _allocated = 1; 56 } 57 // We account region end waste fully to PLAB allocation. This is not completely fair, 58 // but is a conservative assumption because PLABs may be sized flexibly while we 59 // cannot adjust direct allocations. 60 // In some cases, wasted_frac may become > 1 but that just reflects the problem 61 // with region_end_waste. 62 double wasted_frac = (double)(_unused + _wasted + _region_end_waste) / (double)_allocated; 63 size_t target_refills = (size_t)((wasted_frac * TargetSurvivorRatio) / TargetPLABWastePct); 64 if (target_refills == 0) { 65 target_refills = 1; 66 } 67 size_t cur_plab_sz = used() / target_refills; 68 // Take historical weighted average 69 _filter.sample(cur_plab_sz); 70 // Clip from above and below, and align to object boundary 71 size_t plab_sz; 72 plab_sz = MAX2(min_size(), (size_t)_filter.average()); 73 plab_sz = MIN2(max_size(), plab_sz); 74 plab_sz = align_object_size(plab_sz); 75 // Latch the result 76 _desired_net_plab_sz = plab_sz; 77 if (PrintPLAB) { 78 gclog_or_tty->print_cr(" (plab_sz = " SIZE_FORMAT " desired_plab_sz = " SIZE_FORMAT ") ", cur_plab_sz, plab_sz); 79 } 80 } 81 // Clear accumulators for next round. 82 reset(); 83 } 84