diff -r 4e648a2d8480 -r 7893d1012580 src/hotspot/share/gc/cms/cmsArguments.cpp --- a/src/hotspot/share/gc/cms/cmsArguments.cpp Thu Nov 14 12:38:31 2019 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,225 +0,0 @@ -/* - * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2017, Red Hat, Inc. and/or its affiliates. - * 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/cms/cmsArguments.hpp" -#include "gc/cms/cmsHeap.hpp" -#include "gc/cms/compactibleFreeListSpace.hpp" -#include "gc/shared/cardTableRS.hpp" -#include "gc/shared/gcArguments.hpp" -#include "gc/shared/genCollectedHeap.hpp" -#include "gc/shared/workerPolicy.hpp" -#include "runtime/arguments.hpp" -#include "runtime/globals.hpp" -#include "runtime/globals_extension.hpp" -#include "utilities/defaultStream.hpp" - -void CMSArguments::set_parnew_gc_flags() { - assert(!UseSerialGC && !UseParallelOldGC && !UseParallelGC && !UseG1GC, - "control point invariant"); - assert(UseConcMarkSweepGC, "CMS is expected to be on here"); - - if (FLAG_IS_DEFAULT(ParallelGCThreads)) { - FLAG_SET_DEFAULT(ParallelGCThreads, WorkerPolicy::parallel_worker_threads()); - assert(ParallelGCThreads > 0, "We should always have at least one thread by default"); - } else if (ParallelGCThreads == 0) { - jio_fprintf(defaultStream::error_stream(), - "The ParNew GC can not be combined with -XX:ParallelGCThreads=0\n"); - vm_exit(1); - } - - // By default YoungPLABSize and OldPLABSize are set to 4096 and 1024 respectively, - // these settings are default for Parallel Scavenger. For ParNew+Tenured configuration - // we set them to 1024 and 1024. - // See CR 6362902. - if (FLAG_IS_DEFAULT(YoungPLABSize)) { - FLAG_SET_DEFAULT(YoungPLABSize, (intx)1024); - } - if (FLAG_IS_DEFAULT(OldPLABSize)) { - FLAG_SET_DEFAULT(OldPLABSize, (intx)1024); - } - - // When using compressed oops, we use local overflow stacks, - // rather than using a global overflow list chained through - // the klass word of the object's pre-image. - if (UseCompressedOops && !ParGCUseLocalOverflow) { - if (!FLAG_IS_DEFAULT(ParGCUseLocalOverflow)) { - warning("Forcing +ParGCUseLocalOverflow: needed if using compressed references"); - } - FLAG_SET_DEFAULT(ParGCUseLocalOverflow, true); - } - assert(ParGCUseLocalOverflow || !UseCompressedOops, "Error"); -} - -// Adjust some sizes to suit CMS and/or ParNew needs; these work well on -// sparc/solaris for certain applications, but would gain from -// further optimization and tuning efforts, and would almost -// certainly gain from analysis of platform and environment. -void CMSArguments::initialize() { - GCArguments::initialize(); - - assert(!UseSerialGC && !UseParallelOldGC && !UseParallelGC, "Error"); - assert(UseConcMarkSweepGC, "CMS is expected to be on here"); - - // CMS space iteration, which FLSVerifyAllHeapreferences entails, - // insists that we hold the requisite locks so that the iteration is - // MT-safe. For the verification at start-up and shut-down, we don't - // yet have a good way of acquiring and releasing these locks, - // which are not visible at the CollectedHeap level. We want to - // be able to acquire these locks and then do the iteration rather - // than just disable the lock verification. This will be fixed under - // bug 4788986. - if (UseConcMarkSweepGC && FLSVerifyAllHeapReferences) { - if (VerifyDuringStartup) { - warning("Heap verification at start-up disabled " - "(due to current incompatibility with FLSVerifyAllHeapReferences)"); - VerifyDuringStartup = false; // Disable verification at start-up - } - - if (VerifyBeforeExit) { - warning("Heap verification at shutdown disabled " - "(due to current incompatibility with FLSVerifyAllHeapReferences)"); - VerifyBeforeExit = false; // Disable verification at shutdown - } - } - - if (!ClassUnloading) { - FLAG_SET_CMDLINE(CMSClassUnloadingEnabled, false); - } - - // Set CMS global values - CompactibleFreeListSpace::set_cms_values(); - - // Turn off AdaptiveSizePolicy by default for cms until it is complete. - disable_adaptive_size_policy("UseConcMarkSweepGC"); - - set_parnew_gc_flags(); - - size_t max_heap = align_down(MaxHeapSize, - CardTableRS::ct_max_alignment_constraint()); - - // Now make adjustments for CMS - intx tenuring_default = (intx)6; - size_t young_gen_per_worker = CMSYoungGenPerWorker; - - // Preferred young gen size for "short" pauses: - // upper bound depends on # of threads and NewRatio. - const size_t preferred_max_new_size_unaligned = - MIN2(max_heap/(NewRatio+1), ScaleForWordSize(young_gen_per_worker * ParallelGCThreads)); - size_t preferred_max_new_size = - align_up(preferred_max_new_size_unaligned, os::vm_page_size()); - - // Unless explicitly requested otherwise, size young gen - // for "short" pauses ~ CMSYoungGenPerWorker*ParallelGCThreads - - // If either MaxNewSize or NewRatio is set on the command line, - // assume the user is trying to set the size of the young gen. - if (FLAG_IS_DEFAULT(MaxNewSize) && FLAG_IS_DEFAULT(NewRatio)) { - - // Set MaxNewSize to our calculated preferred_max_new_size unless - // NewSize was set on the command line and it is larger than - // preferred_max_new_size. - if (!FLAG_IS_DEFAULT(NewSize)) { // NewSize explicitly set at command-line - FLAG_SET_ERGO(MaxNewSize, MAX2(NewSize, preferred_max_new_size)); - } else { - FLAG_SET_ERGO(MaxNewSize, preferred_max_new_size); - } - log_trace(gc, heap)("CMS ergo set MaxNewSize: " SIZE_FORMAT, MaxNewSize); - - // Code along this path potentially sets NewSize and OldSize - log_trace(gc, heap)("CMS set min_heap_size: " SIZE_FORMAT " initial_heap_size: " SIZE_FORMAT " max_heap: " SIZE_FORMAT, - MinHeapSize, InitialHeapSize, max_heap); - size_t min_new = preferred_max_new_size; - if (FLAG_IS_CMDLINE(NewSize)) { - min_new = NewSize; - } - if (max_heap > min_new && MinHeapSize > min_new) { - // Unless explicitly requested otherwise, make young gen - // at least min_new, and at most preferred_max_new_size. - if (FLAG_IS_DEFAULT(NewSize)) { - FLAG_SET_ERGO(NewSize, MAX2(NewSize, min_new)); - FLAG_SET_ERGO(NewSize, MIN2(preferred_max_new_size, NewSize)); - log_trace(gc, heap)("CMS ergo set NewSize: " SIZE_FORMAT, NewSize); - } - // Unless explicitly requested otherwise, size old gen - // so it's NewRatio x of NewSize. - if (FLAG_IS_DEFAULT(OldSize)) { - if (max_heap > NewSize) { - FLAG_SET_ERGO(OldSize, MIN2(NewRatio*NewSize, max_heap - NewSize)); - log_trace(gc, heap)("CMS ergo set OldSize: " SIZE_FORMAT, OldSize); - } - } - } - } - // Unless explicitly requested otherwise, definitely - // promote all objects surviving "tenuring_default" scavenges. - if (FLAG_IS_DEFAULT(MaxTenuringThreshold) && - FLAG_IS_DEFAULT(SurvivorRatio)) { - FLAG_SET_ERGO(MaxTenuringThreshold, tenuring_default); - } - // If we decided above (or user explicitly requested) - // `promote all' (via MaxTenuringThreshold := 0), - // prefer minuscule survivor spaces so as not to waste - // space for (non-existent) survivors - if (FLAG_IS_DEFAULT(SurvivorRatio) && MaxTenuringThreshold == 0) { - FLAG_SET_ERGO(SurvivorRatio, MAX2((uintx)1024, SurvivorRatio)); - } - - // OldPLABSize is interpreted in CMS as not the size of the PLAB in words, - // but rather the number of free blocks of a given size that are used when - // replenishing the local per-worker free list caches. - if (FLAG_IS_DEFAULT(OldPLABSize)) { - if (!FLAG_IS_DEFAULT(ResizeOldPLAB) && !ResizeOldPLAB) { - // OldPLAB sizing manually turned off: Use a larger default setting, - // unless it was manually specified. This is because a too-low value - // will slow down scavenges. - FLAG_SET_ERGO(OldPLABSize, CompactibleFreeListSpaceLAB::_default_static_old_plab_size); // default value before 6631166 - } else { - FLAG_SET_DEFAULT(OldPLABSize, CompactibleFreeListSpaceLAB::_default_dynamic_old_plab_size); // old CMSParPromoteBlocksToClaim default - } - } - - // If either of the static initialization defaults have changed, note this - // modification. - if (!FLAG_IS_DEFAULT(OldPLABSize) || !FLAG_IS_DEFAULT(OldPLABWeight)) { - CompactibleFreeListSpaceLAB::modify_initialization(OldPLABSize, OldPLABWeight); - } - - log_trace(gc)("MarkStackSize: %uk MarkStackSizeMax: %uk", (unsigned int) (MarkStackSize / K), (uint) (MarkStackSizeMax / K)); -} - -void CMSArguments::disable_adaptive_size_policy(const char* collector_name) { - if (UseAdaptiveSizePolicy) { - if (FLAG_IS_CMDLINE(UseAdaptiveSizePolicy)) { - warning("Disabling UseAdaptiveSizePolicy; it is incompatible with %s.", - collector_name); - } - FLAG_SET_DEFAULT(UseAdaptiveSizePolicy, false); - } -} - -CollectedHeap* CMSArguments::create_heap() { - return new CMSHeap(); -}