Thu, 28 Mar 2013 10:27:28 +0100
7014552: gc/lock/jni/jnilockXXX works too slow on 1-processor machine
Summary: Keep a counter of how many times we were stalled by the GC locker, add a diagnostic flag which sets the limit.
Reviewed-by: brutisso, ehelin, johnc
tonyp@2472 | 1 | /* |
tonyp@2472 | 2 | * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved. |
tonyp@2472 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
tonyp@2472 | 4 | * |
tonyp@2472 | 5 | * This code is free software; you can redistribute it and/or modify it |
tonyp@2472 | 6 | * under the terms of the GNU General Public License version 2 only, as |
tonyp@2472 | 7 | * published by the Free Software Foundation. |
tonyp@2472 | 8 | * |
tonyp@2472 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
tonyp@2472 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
tonyp@2472 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
tonyp@2472 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
tonyp@2472 | 13 | * accompanied this code). |
tonyp@2472 | 14 | * |
tonyp@2472 | 15 | * You should have received a copy of the GNU General Public License version |
tonyp@2472 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
tonyp@2472 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
tonyp@2472 | 18 | * |
tonyp@2472 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
tonyp@2472 | 20 | * or visit www.oracle.com if you need additional information or have any |
tonyp@2472 | 21 | * questions. |
tonyp@2472 | 22 | * |
tonyp@2472 | 23 | */ |
tonyp@2472 | 24 | |
tonyp@2472 | 25 | #include "precompiled.hpp" |
tonyp@2974 | 26 | #include "gc_implementation/g1/heapRegionRemSet.hpp" |
tonyp@2472 | 27 | #include "gc_implementation/g1/heapRegionSets.hpp" |
tonyp@2472 | 28 | |
tonyp@3268 | 29 | // Note on the check_mt_safety() methods below: |
tonyp@3268 | 30 | // |
tonyp@3268 | 31 | // Verification of the "master" heap region sets / lists that are |
tonyp@3268 | 32 | // maintained by G1CollectedHeap is always done during a STW pause and |
tonyp@3268 | 33 | // by the VM thread at the start / end of the pause. The standard |
tonyp@3268 | 34 | // verification methods all assert check_mt_safety(). This is |
tonyp@3268 | 35 | // important as it ensures that verification is done without |
tonyp@3268 | 36 | // concurrent updates taking place at the same time. It follows, that, |
tonyp@3268 | 37 | // for the "master" heap region sets / lists, the check_mt_safety() |
tonyp@3268 | 38 | // method should include the VM thread / STW case. |
tonyp@3268 | 39 | |
tonyp@2472 | 40 | //////////////////// FreeRegionList //////////////////// |
tonyp@2472 | 41 | |
tonyp@2472 | 42 | const char* FreeRegionList::verify_region_extra(HeapRegion* hr) { |
tonyp@2472 | 43 | if (hr->is_young()) { |
tonyp@2472 | 44 | return "the region should not be young"; |
tonyp@2472 | 45 | } |
tonyp@2472 | 46 | // The superclass will check that the region is empty and |
tonyp@3268 | 47 | // not humongous. |
tonyp@2472 | 48 | return HeapRegionLinkedList::verify_region_extra(hr); |
tonyp@2472 | 49 | } |
tonyp@2472 | 50 | |
tonyp@2472 | 51 | //////////////////// MasterFreeRegionList //////////////////// |
tonyp@2472 | 52 | |
tonyp@2974 | 53 | const char* MasterFreeRegionList::verify_region_extra(HeapRegion* hr) { |
tonyp@2974 | 54 | // We should reset the RSet for parallel iteration before we add it |
tonyp@2974 | 55 | // to the master free list so that it is ready when the region is |
tonyp@2974 | 56 | // re-allocated. |
tonyp@2974 | 57 | if (!hr->rem_set()->verify_ready_for_par_iteration()) { |
tonyp@2974 | 58 | return "the region's RSet should be ready for parallel iteration"; |
tonyp@2974 | 59 | } |
tonyp@2974 | 60 | return FreeRegionList::verify_region_extra(hr); |
tonyp@2974 | 61 | } |
tonyp@2974 | 62 | |
tonyp@2472 | 63 | bool MasterFreeRegionList::check_mt_safety() { |
tonyp@2472 | 64 | // Master Free List MT safety protocol: |
tonyp@2472 | 65 | // (a) If we're at a safepoint, operations on the master free list |
tonyp@2472 | 66 | // should be invoked by either the VM thread (which will serialize |
tonyp@2472 | 67 | // them) or by the GC workers while holding the |
tonyp@2472 | 68 | // FreeList_lock. |
tonyp@2472 | 69 | // (b) If we're not at a safepoint, operations on the master free |
tonyp@2472 | 70 | // list should be invoked while holding the Heap_lock. |
tonyp@2472 | 71 | |
tonyp@3268 | 72 | if (SafepointSynchronize::is_at_safepoint()) { |
tonyp@3268 | 73 | guarantee(Thread::current()->is_VM_thread() || |
tonyp@3268 | 74 | FreeList_lock->owned_by_self(), |
tonyp@3268 | 75 | hrs_ext_msg(this, "master free list MT safety protocol " |
tonyp@3268 | 76 | "at a safepoint")); |
tonyp@3268 | 77 | } else { |
tonyp@3268 | 78 | guarantee(Heap_lock->owned_by_self(), |
tonyp@3268 | 79 | hrs_ext_msg(this, "master free list MT safety protocol " |
tonyp@3268 | 80 | "outside a safepoint")); |
tonyp@3268 | 81 | } |
tonyp@2472 | 82 | |
tonyp@2472 | 83 | return FreeRegionList::check_mt_safety(); |
tonyp@2472 | 84 | } |
tonyp@2472 | 85 | |
tonyp@2472 | 86 | //////////////////// SecondaryFreeRegionList //////////////////// |
tonyp@2472 | 87 | |
tonyp@2472 | 88 | bool SecondaryFreeRegionList::check_mt_safety() { |
tonyp@2472 | 89 | // Secondary Free List MT safety protocol: |
tonyp@2472 | 90 | // Operations on the secondary free list should always be invoked |
tonyp@2472 | 91 | // while holding the SecondaryFreeList_lock. |
tonyp@2472 | 92 | |
tonyp@2472 | 93 | guarantee(SecondaryFreeList_lock->owned_by_self(), |
tonyp@2643 | 94 | hrs_ext_msg(this, "secondary free list MT safety protocol")); |
tonyp@2472 | 95 | |
tonyp@2472 | 96 | return FreeRegionList::check_mt_safety(); |
tonyp@2472 | 97 | } |
tonyp@2472 | 98 | |
tonyp@3268 | 99 | //////////////////// OldRegionSet //////////////////// |
tonyp@3268 | 100 | |
tonyp@3268 | 101 | const char* OldRegionSet::verify_region_extra(HeapRegion* hr) { |
tonyp@3268 | 102 | if (hr->is_young()) { |
tonyp@3268 | 103 | return "the region should not be young"; |
tonyp@3268 | 104 | } |
tonyp@3268 | 105 | // The superclass will check that the region is not empty and not |
tonyp@3268 | 106 | // humongous. |
tonyp@3268 | 107 | return HeapRegionSet::verify_region_extra(hr); |
tonyp@3268 | 108 | } |
tonyp@3268 | 109 | |
tonyp@3268 | 110 | //////////////////// MasterOldRegionSet //////////////////// |
tonyp@3268 | 111 | |
tonyp@3268 | 112 | bool MasterOldRegionSet::check_mt_safety() { |
tonyp@3268 | 113 | // Master Old Set MT safety protocol: |
tonyp@3268 | 114 | // (a) If we're at a safepoint, operations on the master old set |
tonyp@3268 | 115 | // should be invoked: |
tonyp@3268 | 116 | // - by the VM thread (which will serialize them), or |
tonyp@3268 | 117 | // - by the GC workers while holding the FreeList_lock, if we're |
tonyp@3268 | 118 | // at a safepoint for an evacuation pause (this lock is taken |
tonyp@3268 | 119 | // anyway when an GC alloc region is retired so that a new one |
tonyp@3268 | 120 | // is allocated from the free list), or |
tonyp@3268 | 121 | // - by the GC workers while holding the OldSets_lock, if we're at a |
tonyp@3268 | 122 | // safepoint for a cleanup pause. |
tonyp@3268 | 123 | // (b) If we're not at a safepoint, operations on the master old set |
tonyp@3268 | 124 | // should be invoked while holding the Heap_lock. |
tonyp@3268 | 125 | |
tonyp@3268 | 126 | if (SafepointSynchronize::is_at_safepoint()) { |
tonyp@3268 | 127 | guarantee(Thread::current()->is_VM_thread() || |
tonyp@3268 | 128 | _phase == HRSPhaseEvacuation && FreeList_lock->owned_by_self() || |
tonyp@3268 | 129 | _phase == HRSPhaseCleanup && OldSets_lock->owned_by_self(), |
tonyp@3268 | 130 | hrs_ext_msg(this, "master old set MT safety protocol " |
tonyp@3268 | 131 | "at a safepoint")); |
tonyp@3268 | 132 | } else { |
tonyp@3268 | 133 | guarantee(Heap_lock->owned_by_self(), |
tonyp@3268 | 134 | hrs_ext_msg(this, "master old set MT safety protocol " |
tonyp@3268 | 135 | "outside a safepoint")); |
tonyp@3268 | 136 | } |
tonyp@3268 | 137 | |
tonyp@3268 | 138 | return OldRegionSet::check_mt_safety(); |
tonyp@3268 | 139 | } |
tonyp@3268 | 140 | |
tonyp@2472 | 141 | //////////////////// HumongousRegionSet //////////////////// |
tonyp@2472 | 142 | |
tonyp@2472 | 143 | const char* HumongousRegionSet::verify_region_extra(HeapRegion* hr) { |
tonyp@2472 | 144 | if (hr->is_young()) { |
tonyp@2472 | 145 | return "the region should not be young"; |
tonyp@2472 | 146 | } |
tonyp@2472 | 147 | // The superclass will check that the region is not empty and |
tonyp@2472 | 148 | // humongous. |
tonyp@2472 | 149 | return HeapRegionSet::verify_region_extra(hr); |
tonyp@2472 | 150 | } |
tonyp@2472 | 151 | |
tonyp@2643 | 152 | //////////////////// MasterHumongousRegionSet //////////////////// |
tonyp@2472 | 153 | |
tonyp@2472 | 154 | bool MasterHumongousRegionSet::check_mt_safety() { |
tonyp@2472 | 155 | // Master Humongous Set MT safety protocol: |
tonyp@2472 | 156 | // (a) If we're at a safepoint, operations on the master humongous |
tonyp@2472 | 157 | // set should be invoked by either the VM thread (which will |
tonyp@2472 | 158 | // serialize them) or by the GC workers while holding the |
tonyp@2472 | 159 | // OldSets_lock. |
tonyp@2472 | 160 | // (b) If we're not at a safepoint, operations on the master |
tonyp@2472 | 161 | // humongous set should be invoked while holding the Heap_lock. |
tonyp@2472 | 162 | |
tonyp@3268 | 163 | if (SafepointSynchronize::is_at_safepoint()) { |
tonyp@3268 | 164 | guarantee(Thread::current()->is_VM_thread() || |
tonyp@3268 | 165 | OldSets_lock->owned_by_self(), |
tonyp@3268 | 166 | hrs_ext_msg(this, "master humongous set MT safety protocol " |
tonyp@3268 | 167 | "at a safepoint")); |
tonyp@3268 | 168 | } else { |
tonyp@3268 | 169 | guarantee(Heap_lock->owned_by_self(), |
tonyp@3268 | 170 | hrs_ext_msg(this, "master humongous set MT safety protocol " |
tonyp@3268 | 171 | "outside a safepoint")); |
tonyp@3268 | 172 | } |
tonyp@3268 | 173 | |
tonyp@2472 | 174 | return HumongousRegionSet::check_mt_safety(); |
tonyp@2472 | 175 | } |