/* * Copyright (c) 2011, 2019, 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 "aot/aotLoader.hpp" #include "gc/shared/collectedHeap.hpp" #include "logging/log.hpp" #include "logging/logStream.hpp" #include "memory/filemap.hpp" #include "memory/metaspace.hpp" #include "memory/metaspaceShared.hpp" #include "memory/metaspaceTracer.hpp" #include "memory/metaspace/chunkManager.hpp" #include "memory/metaspace/classLoaderMetaspace.hpp" #include "memory/metaspace/commitLimiter.hpp" #include "memory/metaspace/metaspaceCommon.hpp" #include "memory/metaspace/metaspaceEnums.hpp" #include "memory/metaspace/metaspaceReport.hpp" #include "memory/metaspace/metaspaceSizesSnapshot.hpp" #include "memory/metaspace/runningCounters.hpp" #include "memory/metaspace/virtualSpaceList.hpp" #include "memory/universe.hpp" #include "oops/compressedOops.hpp" #include "runtime/init.hpp" #include "runtime/java.hpp" #include "runtime/orderAccess.hpp" #include "services/memTracker.hpp" #include "utilities/copy.hpp" #include "utilities/debug.hpp" #include "utilities/formatBuffer.hpp" #include "utilities/globalDefinitions.hpp" using metaspace::ChunkManager; using metaspace::ClassLoaderMetaspace; using metaspace::CommitLimiter; using metaspace::MetaspaceType; using metaspace::MetadataType; using metaspace::MetaspaceReporter; using metaspace::RunningCounters; using metaspace::VirtualSpaceList; // Used by MetaspaceCounters size_t MetaspaceUtils::free_chunks_total_words(MetadataType mdtype) { return is_class(mdtype) ? RunningCounters::free_chunks_words_class() : RunningCounters::free_chunks_words_nonclass(); } size_t MetaspaceUtils::used_words() { return RunningCounters::used_words(); } size_t MetaspaceUtils::used_words(MetadataType mdtype) { return is_class(mdtype) ? RunningCounters::used_words_class() : RunningCounters::used_words_nonclass(); } size_t MetaspaceUtils::reserved_words() { return RunningCounters::reserved_words(); } size_t MetaspaceUtils::reserved_words(MetadataType mdtype) { return is_class(mdtype) ? RunningCounters::reserved_words_class() : RunningCounters::reserved_words_nonclass(); } size_t MetaspaceUtils::committed_words() { return RunningCounters::committed_words(); } size_t MetaspaceUtils::committed_words(MetadataType mdtype) { return is_class(mdtype) ? RunningCounters::committed_words_class() : RunningCounters::committed_words_nonclass(); } void MetaspaceUtils::print_metaspace_change(const metaspace::MetaspaceSizesSnapshot& pre_meta_values) { const metaspace::MetaspaceSizesSnapshot meta_values; // We print used and committed since these are the most useful at-a-glance vitals for Metaspace: // - used tells you how much memory is actually used for metadata // - committed tells you how much memory is committed for the purpose of metadata // The difference between those two would be waste, which can have various forms (freelists, // unused parts of committed chunks etc) // // Left out is reserved, since this is not as exciting as the first two values: for class space, // it is a constant (to uninformed users, often confusingly large). For non-class space, it would // be interesting since free chunks can be uncommitted, but for now it is left out. if (Metaspace::using_class_space()) { log_info(gc, metaspace)(HEAP_CHANGE_FORMAT" " HEAP_CHANGE_FORMAT" " HEAP_CHANGE_FORMAT, HEAP_CHANGE_FORMAT_ARGS("Metaspace", pre_meta_values.used(), pre_meta_values.committed(), meta_values.used(), meta_values.committed()), HEAP_CHANGE_FORMAT_ARGS("NonClass", pre_meta_values.non_class_used(), pre_meta_values.non_class_committed(), meta_values.non_class_used(), meta_values.non_class_committed()), HEAP_CHANGE_FORMAT_ARGS("Class", pre_meta_values.class_used(), pre_meta_values.class_committed(), meta_values.class_used(), meta_values.class_committed())); } else { log_info(gc, metaspace)(HEAP_CHANGE_FORMAT, HEAP_CHANGE_FORMAT_ARGS("Metaspace", pre_meta_values.used(), pre_meta_values.committed(), meta_values.used(), meta_values.committed())); } } // Prints an ASCII representation of the given space. void MetaspaceUtils::print_metaspace_map(outputStream* out, MetadataType mdtype) { out->print_cr("-- not yet implemented ---"); } // This will print out a basic metaspace usage report but // unlike print_report() is guaranteed not to lock or to walk the CLDG. void MetaspaceUtils::print_basic_report(outputStream* out, size_t scale) { MetaspaceReporter::print_basic_report(out, scale); } // Prints a report about the current metaspace state. // Optional parts can be enabled via flags. // Function will walk the CLDG and will lock the expand lock; if that is not // convenient, use print_basic_report() instead. void MetaspaceUtils::print_full_report(outputStream* out, size_t scale) { const int flags = MetaspaceReporter::rf_show_loaders | MetaspaceReporter::rf_break_down_by_chunktype | MetaspaceReporter::rf_show_classes; MetaspaceReporter::print_report(out, scale, flags); } void MetaspaceUtils::print_on(outputStream* out) { // Used from all GCs. It first prints out totals, then, separately, the class space portion. out->print_cr(" Metaspace " "used " SIZE_FORMAT "K, " "committed " SIZE_FORMAT "K, " "reserved " SIZE_FORMAT "K", used_bytes()/K, committed_bytes()/K, reserved_bytes()/K); if (Metaspace::using_class_space()) { const MetadataType ct = metaspace::ClassType; out->print_cr(" class space " "used " SIZE_FORMAT "K, " "committed " SIZE_FORMAT "K, " "reserved " SIZE_FORMAT "K", used_bytes(ct)/K, committed_bytes(ct)/K, reserved_bytes(ct)/K); } } #ifdef ASSERT void MetaspaceUtils::verify(bool slow) { if (Metaspace::initialized()) { // Verify non-class chunkmanager... ChunkManager* cm = ChunkManager::chunkmanager_nonclass(); cm->verify(slow); // ... and space list. VirtualSpaceList* vsl = VirtualSpaceList::vslist_nonclass(); vsl->verify(slow); if (Metaspace::using_class_space()) { // If we use compressed class pointers, verify class chunkmanager... cm = ChunkManager::chunkmanager_class(); assert(cm != NULL, "Sanity"); cm->verify(slow); // ... and class spacelist. VirtualSpaceList* vsl = VirtualSpaceList::vslist_nonclass(); assert(vsl != NULL, "Sanity"); vsl->verify(slow); } } } #endif ////////////////////////////////7 // MetaspaceGC methods volatile size_t MetaspaceGC::_capacity_until_GC = 0; uint MetaspaceGC::_shrink_factor = 0; bool MetaspaceGC::_should_concurrent_collect = false; // VM_CollectForMetadataAllocation is the vm operation used to GC. // Within the VM operation after the GC the attempt to allocate the metadata // should succeed. If the GC did not free enough space for the metaspace // allocation, the HWM is increased so that another virtualspace will be // allocated for the metadata. With perm gen the increase in the perm // gen had bounds, MinMetaspaceExpansion and MaxMetaspaceExpansion. The // metaspace policy uses those as the small and large steps for the HWM. // // After the GC the compute_new_size() for MetaspaceGC is called to // resize the capacity of the metaspaces. The current implementation // is based on the flags MinMetaspaceFreeRatio and MaxMetaspaceFreeRatio used // to resize the Java heap by some GC's. New flags can be implemented // if really needed. MinMetaspaceFreeRatio is used to calculate how much // free space is desirable in the metaspace capacity to decide how much // to increase the HWM. MaxMetaspaceFreeRatio is used to decide how much // free space is desirable in the metaspace capacity before decreasing // the HWM. // Calculate the amount to increase the high water mark (HWM). // Increase by a minimum amount (MinMetaspaceExpansion) so that // another expansion is not requested too soon. If that is not // enough to satisfy the allocation, increase by MaxMetaspaceExpansion. // If that is still not enough, expand by the size of the allocation // plus some. size_t MetaspaceGC::delta_capacity_until_GC(size_t bytes) { size_t min_delta = MinMetaspaceExpansion; size_t max_delta = MaxMetaspaceExpansion; size_t delta = align_up(bytes, Metaspace::commit_alignment()); if (delta <= min_delta) { delta = min_delta; } else if (delta <= max_delta) { // Don't want to hit the high water mark on the next // allocation so make the delta greater than just enough // for this allocation. delta = max_delta; } else { // This allocation is large but the next ones are probably not // so increase by the minimum. delta = delta + min_delta; } assert_is_aligned(delta, Metaspace::commit_alignment()); return delta; } size_t MetaspaceGC::capacity_until_GC() { size_t value = OrderAccess::load_acquire(&_capacity_until_GC); assert(value >= MetaspaceSize, "Not initialized properly?"); return value; } // Try to increase the _capacity_until_GC limit counter by v bytes. // Returns true if it succeeded. It may fail if either another thread // concurrently increased the limit or the new limit would be larger // than MaxMetaspaceSize. // On success, optionally returns new and old metaspace capacity in // new_cap_until_GC and old_cap_until_GC respectively. // On error, optionally sets can_retry to indicate whether if there is // actually enough space remaining to satisfy the request. bool MetaspaceGC::inc_capacity_until_GC(size_t v, size_t* new_cap_until_GC, size_t* old_cap_until_GC, bool* can_retry) { assert_is_aligned(v, Metaspace::commit_alignment()); size_t old_capacity_until_GC = _capacity_until_GC; size_t new_value = old_capacity_until_GC + v; if (new_value < old_capacity_until_GC) { // The addition wrapped around, set new_value to aligned max value. new_value = align_down(max_uintx, Metaspace::commit_alignment()); } if (new_value > MaxMetaspaceSize) { if (can_retry != NULL) { *can_retry = false; } return false; } if (can_retry != NULL) { *can_retry = true; } size_t prev_value = Atomic::cmpxchg(new_value, &_capacity_until_GC, old_capacity_until_GC); if (old_capacity_until_GC != prev_value) { return false; } if (new_cap_until_GC != NULL) { *new_cap_until_GC = new_value; } if (old_cap_until_GC != NULL) { *old_cap_until_GC = old_capacity_until_GC; } return true; } size_t MetaspaceGC::dec_capacity_until_GC(size_t v) { assert_is_aligned(v, Metaspace::commit_alignment()); return Atomic::sub(v, &_capacity_until_GC); } void MetaspaceGC::initialize() { // Set the high-water mark to MaxMetapaceSize during VM initializaton since // we can't do a GC during initialization. _capacity_until_GC = MaxMetaspaceSize; } void MetaspaceGC::post_initialize() { // Reset the high-water mark once the VM initialization is done. _capacity_until_GC = MAX2(MetaspaceUtils::committed_bytes(), MetaspaceSize); } bool MetaspaceGC::can_expand(size_t word_size, bool is_class) { // Check if the compressed class space is full. if (is_class && Metaspace::using_class_space()) { size_t class_committed = MetaspaceUtils::committed_bytes(metaspace::ClassType); if (class_committed + word_size * BytesPerWord > CompressedClassSpaceSize) { log_trace(gc, metaspace, freelist)("Cannot expand %s metaspace by " SIZE_FORMAT " words (CompressedClassSpaceSize = " SIZE_FORMAT " words)", (is_class ? "class" : "non-class"), word_size, CompressedClassSpaceSize / sizeof(MetaWord)); return false; } } // Check if the user has imposed a limit on the metaspace memory. size_t committed_bytes = MetaspaceUtils::committed_bytes(); if (committed_bytes + word_size * BytesPerWord > MaxMetaspaceSize) { log_trace(gc, metaspace, freelist)("Cannot expand %s metaspace by " SIZE_FORMAT " words (MaxMetaspaceSize = " SIZE_FORMAT " words)", (is_class ? "class" : "non-class"), word_size, MaxMetaspaceSize / sizeof(MetaWord)); return false; } return true; } size_t MetaspaceGC::allowed_expansion() { size_t committed_bytes = MetaspaceUtils::committed_bytes(); size_t capacity_until_gc = capacity_until_GC(); assert(capacity_until_gc >= committed_bytes, "capacity_until_gc: " SIZE_FORMAT " < committed_bytes: " SIZE_FORMAT, capacity_until_gc, committed_bytes); size_t left_until_max = MaxMetaspaceSize - committed_bytes; size_t left_until_GC = capacity_until_gc - committed_bytes; size_t left_to_commit = MIN2(left_until_GC, left_until_max); log_trace(gc, metaspace, freelist)("allowed expansion words: " SIZE_FORMAT " (left_until_max: " SIZE_FORMAT ", left_until_GC: " SIZE_FORMAT ".", left_to_commit / BytesPerWord, left_until_max / BytesPerWord, left_until_GC / BytesPerWord); return left_to_commit / BytesPerWord; } void MetaspaceGC::compute_new_size() { assert(_shrink_factor <= 100, "invalid shrink factor"); uint current_shrink_factor = _shrink_factor; _shrink_factor = 0; // Using committed_bytes() for used_after_gc is an overestimation, since the // chunk free lists are included in committed_bytes() and the memory in an // un-fragmented chunk free list is available for future allocations. // However, if the chunk free lists becomes fragmented, then the memory may // not be available for future allocations and the memory is therefore "in use". // Including the chunk free lists in the definition of "in use" is therefore // necessary. Not including the chunk free lists can cause capacity_until_GC to // shrink below committed_bytes() and this has caused serious bugs in the past. const size_t used_after_gc = MetaspaceUtils::committed_bytes(); const size_t capacity_until_GC = MetaspaceGC::capacity_until_GC(); const double minimum_free_percentage = MinMetaspaceFreeRatio / 100.0; const double maximum_used_percentage = 1.0 - minimum_free_percentage; const double min_tmp = used_after_gc / maximum_used_percentage; size_t minimum_desired_capacity = (size_t)MIN2(min_tmp, double(MaxMetaspaceSize)); // Don't shrink less than the initial generation size minimum_desired_capacity = MAX2(minimum_desired_capacity, MetaspaceSize); log_trace(gc, metaspace)("MetaspaceGC::compute_new_size: "); log_trace(gc, metaspace)(" minimum_free_percentage: %6.2f maximum_used_percentage: %6.2f", minimum_free_percentage, maximum_used_percentage); log_trace(gc, metaspace)(" used_after_gc : %6.1fKB", used_after_gc / (double) K); size_t shrink_bytes = 0; if (capacity_until_GC < minimum_desired_capacity) { // If we have less capacity below the metaspace HWM, then // increment the HWM. size_t expand_bytes = minimum_desired_capacity - capacity_until_GC; expand_bytes = align_up(expand_bytes, Metaspace::commit_alignment()); // Don't expand unless it's significant if (expand_bytes >= MinMetaspaceExpansion) { size_t new_capacity_until_GC = 0; bool succeeded = MetaspaceGC::inc_capacity_until_GC(expand_bytes, &new_capacity_until_GC); assert(succeeded, "Should always succesfully increment HWM when at safepoint"); Metaspace::tracer()->report_gc_threshold(capacity_until_GC, new_capacity_until_GC, MetaspaceGCThresholdUpdater::ComputeNewSize); log_trace(gc, metaspace)(" expanding: minimum_desired_capacity: %6.1fKB expand_bytes: %6.1fKB MinMetaspaceExpansion: %6.1fKB new metaspace HWM: %6.1fKB", minimum_desired_capacity / (double) K, expand_bytes / (double) K, MinMetaspaceExpansion / (double) K, new_capacity_until_GC / (double) K); } return; } // No expansion, now see if we want to shrink // We would never want to shrink more than this assert(capacity_until_GC >= minimum_desired_capacity, SIZE_FORMAT " >= " SIZE_FORMAT, capacity_until_GC, minimum_desired_capacity); size_t max_shrink_bytes = capacity_until_GC - minimum_desired_capacity; // Should shrinking be considered? if (MaxMetaspaceFreeRatio < 100) { const double maximum_free_percentage = MaxMetaspaceFreeRatio / 100.0; const double minimum_used_percentage = 1.0 - maximum_free_percentage; const double max_tmp = used_after_gc / minimum_used_percentage; size_t maximum_desired_capacity = (size_t)MIN2(max_tmp, double(MaxMetaspaceSize)); maximum_desired_capacity = MAX2(maximum_desired_capacity, MetaspaceSize); log_trace(gc, metaspace)(" maximum_free_percentage: %6.2f minimum_used_percentage: %6.2f", maximum_free_percentage, minimum_used_percentage); log_trace(gc, metaspace)(" minimum_desired_capacity: %6.1fKB maximum_desired_capacity: %6.1fKB", minimum_desired_capacity / (double) K, maximum_desired_capacity / (double) K); assert(minimum_desired_capacity <= maximum_desired_capacity, "sanity check"); if (capacity_until_GC > maximum_desired_capacity) { // Capacity too large, compute shrinking size shrink_bytes = capacity_until_GC - maximum_desired_capacity; // We don't want shrink all the way back to initSize if people call // System.gc(), because some programs do that between "phases" and then // we'd just have to grow the heap up again for the next phase. So we // damp the shrinking: 0% on the first call, 10% on the second call, 40% // on the third call, and 100% by the fourth call. But if we recompute // size without shrinking, it goes back to 0%. shrink_bytes = shrink_bytes / 100 * current_shrink_factor; shrink_bytes = align_down(shrink_bytes, Metaspace::commit_alignment()); assert(shrink_bytes <= max_shrink_bytes, "invalid shrink size " SIZE_FORMAT " not <= " SIZE_FORMAT, shrink_bytes, max_shrink_bytes); if (current_shrink_factor == 0) { _shrink_factor = 10; } else { _shrink_factor = MIN2(current_shrink_factor * 4, (uint) 100); } log_trace(gc, metaspace)(" shrinking: initThreshold: %.1fK maximum_desired_capacity: %.1fK", MetaspaceSize / (double) K, maximum_desired_capacity / (double) K); log_trace(gc, metaspace)(" shrink_bytes: %.1fK current_shrink_factor: %d new shrink factor: %d MinMetaspaceExpansion: %.1fK", shrink_bytes / (double) K, current_shrink_factor, _shrink_factor, MinMetaspaceExpansion / (double) K); } } // Don't shrink unless it's significant if (shrink_bytes >= MinMetaspaceExpansion && ((capacity_until_GC - shrink_bytes) >= MetaspaceSize)) { size_t new_capacity_until_GC = MetaspaceGC::dec_capacity_until_GC(shrink_bytes); Metaspace::tracer()->report_gc_threshold(capacity_until_GC, new_capacity_until_GC, MetaspaceGCThresholdUpdater::ComputeNewSize); } } ////// Metaspace methods ///// MetaWord* Metaspace::_compressed_class_space_base = NULL; size_t Metaspace::_compressed_class_space_size = 0; const MetaspaceTracer* Metaspace::_tracer = NULL; bool Metaspace::_initialized = false; size_t Metaspace::_commit_alignment = 0; size_t Metaspace::_reserve_alignment = 0; DEBUG_ONLY(bool Metaspace::_frozen = false;) #ifdef _LP64 static const uint64_t UnscaledClassSpaceMax = (uint64_t(max_juint) + 1); void Metaspace::set_narrow_klass_base_and_shift(address metaspace_base, address cds_base) { assert(!DumpSharedSpaces, "narrow_klass is set by MetaspaceShared class."); // Figure out the narrow_klass_base and the narrow_klass_shift. The // narrow_klass_base is the lower of the metaspace base and the cds base // (if cds is enabled). The narrow_klass_shift depends on the distance // between the lower base and higher address. address lower_base; address higher_address; #if INCLUDE_CDS if (UseSharedSpaces) { higher_address = MAX2((address)(cds_base + MetaspaceShared::core_spaces_size()), (address)(metaspace_base + compressed_class_space_size())); lower_base = MIN2(metaspace_base, cds_base); } else #endif { higher_address = metaspace_base + compressed_class_space_size(); lower_base = metaspace_base; uint64_t klass_encoding_max = UnscaledClassSpaceMax << LogKlassAlignmentInBytes; // If compressed class space fits in lower 32G, we don't need a base. if (higher_address <= (address)klass_encoding_max) { lower_base = 0; // Effectively lower base is zero. } } CompressedKlassPointers::set_base(lower_base); // CDS uses LogKlassAlignmentInBytes for narrow_klass_shift. See // MetaspaceShared::initialize_dumptime_shared_and_meta_spaces() for // how dump time narrow_klass_shift is set. Although, CDS can work // with zero-shift mode also, to be consistent with AOT it uses // LogKlassAlignmentInBytes for klass shift so archived java heap objects // can be used at same time as AOT code. if (!UseSharedSpaces && (uint64_t)(higher_address - lower_base) <= UnscaledClassSpaceMax) { CompressedKlassPointers::set_shift(0); } else { CompressedKlassPointers::set_shift(LogKlassAlignmentInBytes); } AOTLoader::set_narrow_klass_shift(); } #if INCLUDE_CDS // Return TRUE if the specified metaspace_base and cds_base are close enough // to work with compressed klass pointers. bool Metaspace::can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base) { assert(cds_base != 0 && UseSharedSpaces, "Only use with CDS"); assert(UseCompressedClassPointers, "Only use with CompressedKlassPtrs"); address lower_base = MIN2((address)metaspace_base, cds_base); address higher_address = MAX2((address)(cds_base + MetaspaceShared::core_spaces_size()), (address)(metaspace_base + compressed_class_space_size())); return ((uint64_t)(higher_address - lower_base) <= UnscaledClassSpaceMax); } #endif // Try to allocate the metaspace at the requested addr. void Metaspace::allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base) { assert(!DumpSharedSpaces, "compress klass space is allocated by MetaspaceShared class."); assert(using_class_space(), "called improperly"); assert(UseCompressedClassPointers, "Only use with CompressedKlassPtrs"); assert(compressed_class_space_size() < KlassEncodingMetaspaceMax, "Metaspace size is too big"); assert_is_aligned(requested_addr, _reserve_alignment); assert_is_aligned(cds_base, _reserve_alignment); assert_is_aligned(compressed_class_space_size(), _reserve_alignment); // Don't use large pages for the class space. bool large_pages = false; #if !(defined(AARCH64) || defined(AIX)) ReservedSpace rs = ReservedSpace(compressed_class_space_size(), _reserve_alignment, large_pages, requested_addr); #else // AARCH64 ReservedSpace rs; // Our compressed klass pointers may fit nicely into the lower 32 // bits. if ((uint64_t)requested_addr + compressed_class_space_size() < 4*G) { rs = ReservedSpace(compressed_class_space_size(), _reserve_alignment, large_pages, requested_addr); } if (! rs.is_reserved()) { // Aarch64: Try to align metaspace so that we can decode a compressed // klass with a single MOVK instruction. We can do this iff the // compressed class base is a multiple of 4G. // Aix: Search for a place where we can find memory. If we need to load // the base, 4G alignment is helpful, too. size_t increment = AARCH64_ONLY(4*)G; for (char *a = align_up(requested_addr, increment); a < (char*)(1024*G); a += increment) { if (a == (char *)(32*G)) { // Go faster from here on. Zero-based is no longer possible. increment = 4*G; } #if INCLUDE_CDS if (UseSharedSpaces && ! can_use_cds_with_metaspace_addr(a, cds_base)) { // We failed to find an aligned base that will reach. Fall // back to using our requested addr. rs = ReservedSpace(compressed_class_space_size(), _reserve_alignment, large_pages, requested_addr); break; } #endif rs = ReservedSpace(compressed_class_space_size(), _reserve_alignment, large_pages, a); if (rs.is_reserved()) break; } } #endif // AARCH64 if (!rs.is_reserved()) { #if INCLUDE_CDS if (UseSharedSpaces) { size_t increment = align_up(1*G, _reserve_alignment); // Keep trying to allocate the metaspace, increasing the requested_addr // by 1GB each time, until we reach an address that will no longer allow // use of CDS with compressed klass pointers. char *addr = requested_addr; while (!rs.is_reserved() && (addr + increment > addr) && can_use_cds_with_metaspace_addr(addr + increment, cds_base)) { addr = addr + increment; rs = ReservedSpace(compressed_class_space_size(), _reserve_alignment, large_pages, addr); } } #endif // If no successful allocation then try to allocate the space anywhere. If // that fails then OOM doom. At this point we cannot try allocating the // metaspace as if UseCompressedClassPointers is off because too much // initialization has happened that depends on UseCompressedClassPointers. // So, UseCompressedClassPointers cannot be turned off at this point. if (!rs.is_reserved()) { rs = ReservedSpace(compressed_class_space_size(), _reserve_alignment, large_pages); if (!rs.is_reserved()) { vm_exit_during_initialization(err_msg("Could not allocate metaspace: " SIZE_FORMAT " bytes", compressed_class_space_size())); } } } // If we got here then the metaspace got allocated. MemTracker::record_virtual_memory_type((address)rs.base(), mtClass); _compressed_class_space_base = (MetaWord*)rs.base(); #if INCLUDE_CDS // Verify that we can use shared spaces. Otherwise, turn off CDS. if (UseSharedSpaces && !can_use_cds_with_metaspace_addr(rs.base(), cds_base)) { FileMapInfo::stop_sharing_and_unmap( "Could not allocate metaspace at a compatible address"); } #endif set_narrow_klass_base_and_shift((address)rs.base(), UseSharedSpaces ? (address)cds_base : 0); initialize_class_space(rs); LogTarget(Trace, gc, metaspace) lt; if (lt.is_enabled()) { ResourceMark rm; LogStream ls(lt); print_compressed_class_space(&ls, requested_addr); } } // For UseCompressedClassPointers the class space is reserved above the top of // the Java heap. The argument passed in is at the base of the compressed space. void Metaspace::initialize_class_space(ReservedSpace rs) { // The reserved space size may be bigger because of alignment, esp with UseLargePages assert(rs.size() >= CompressedClassSpaceSize, SIZE_FORMAT " != " SIZE_FORMAT, rs.size(), CompressedClassSpaceSize); assert(using_class_space(), "Must be using class space"); VirtualSpaceList* vsl = new VirtualSpaceList("class space list", rs, CommitLimiter::globalLimiter()); VirtualSpaceList::set_vslist_class(vsl); ChunkManager* cm = new ChunkManager("class space chunk manager", vsl); ChunkManager::set_chunkmanager_class(cm); } void Metaspace::print_compressed_class_space(outputStream* st, const char* requested_addr) { st->print_cr("Narrow klass base: " PTR_FORMAT ", Narrow klass shift: %d", p2i(CompressedKlassPointers::base()), CompressedKlassPointers::shift()); if (Metaspace::using_class_space()) { st->print("Compressed class space size: " SIZE_FORMAT " Address: " PTR_FORMAT, compressed_class_space_size(), p2i(compressed_class_space_base())); if (requested_addr != 0) { st->print(" Req Addr: " PTR_FORMAT, p2i(requested_addr)); } st->cr(); } } #endif void Metaspace::ergo_initialize() { if (DumpSharedSpaces) { // Using large pages when dumping the shared archive is currently not implemented. FLAG_SET_ERGO(UseLargePagesInMetaspace, false); } size_t page_size = os::vm_page_size(); if (UseLargePages && UseLargePagesInMetaspace) { page_size = os::large_page_size(); } // Commit alignment: (I would rather hide this since this is an implementation detail but we need it // when calculating the gc threshold). _commit_alignment = metaspace::constants::commit_granule_bytes; // Reserve alignment: all Metaspace memory mappings are to be aligned to the size of a root chunk. _reserve_alignment = MAX2(page_size, (size_t)metaspace::chklvl::MAX_CHUNK_BYTE_SIZE); assert(is_aligned(_reserve_alignment, os::vm_allocation_granularity()), "root chunk size must be a multiple of alloc granularity"); // Do not use FLAG_SET_ERGO to update MaxMetaspaceSize, since this will // override if MaxMetaspaceSize was set on the command line or not. // This information is needed later to conform to the specification of the // java.lang.management.MemoryUsage API. // // Ideally, we would be able to set the default value of MaxMetaspaceSize in // globals.hpp to the aligned value, but this is not possible, since the // alignment depends on other flags being parsed. MaxMetaspaceSize = align_down_bounded(MaxMetaspaceSize, _reserve_alignment); if (MetaspaceSize > MaxMetaspaceSize) { MetaspaceSize = MaxMetaspaceSize; } MetaspaceSize = align_down_bounded(MetaspaceSize, _commit_alignment); assert(MetaspaceSize <= MaxMetaspaceSize, "MetaspaceSize should be limited by MaxMetaspaceSize"); MinMetaspaceExpansion = align_down_bounded(MinMetaspaceExpansion, _commit_alignment); MaxMetaspaceExpansion = align_down_bounded(MaxMetaspaceExpansion, _commit_alignment); CompressedClassSpaceSize = align_down_bounded(CompressedClassSpaceSize, _reserve_alignment); // Note: InitialBootClassLoaderMetaspaceSize is an old parameter which is used to determine the chunk size // of the first non-class chunk handed to the boot class loader. See metaspace/chunkAllocSequence.hpp. size_t min_metaspace_sz = align_up(InitialBootClassLoaderMetaspaceSize, _reserve_alignment); if (UseCompressedClassPointers) { if (min_metaspace_sz >= MaxMetaspaceSize) { vm_exit_during_initialization("MaxMetaspaceSize is too small."); } else if ((min_metaspace_sz + CompressedClassSpaceSize) > MaxMetaspaceSize) { FLAG_SET_ERGO(CompressedClassSpaceSize, MaxMetaspaceSize - min_metaspace_sz); } } else if (min_metaspace_sz >= MaxMetaspaceSize) { FLAG_SET_ERGO(InitialBootClassLoaderMetaspaceSize, min_metaspace_sz); } _compressed_class_space_size = CompressedClassSpaceSize; } void Metaspace::global_initialize() { MetaspaceGC::initialize(); // <- since we do not prealloc init chunks anymore is this still needed? #if INCLUDE_CDS if (DumpSharedSpaces) { MetaspaceShared::initialize_dumptime_shared_and_meta_spaces(); } else if (UseSharedSpaces) { // If any of the archived space fails to map, UseSharedSpaces // is reset to false. Fall through to the // (!DumpSharedSpaces && !UseSharedSpaces) case to set up class // metaspace. MetaspaceShared::initialize_runtime_shared_and_meta_spaces(); } if (DynamicDumpSharedSpaces && !UseSharedSpaces) { vm_exit_during_initialization("DynamicDumpSharedSpaces is unsupported when base CDS archive is not loaded", NULL); } #endif // INCLUDE_CDS // Initialize class space: if (CDS_ONLY(!DumpSharedSpaces && !UseSharedSpaces) NOT_CDS(true)) { #ifdef _LP64 if (using_class_space()) { char* base = (char*)align_up(Universe::heap()->reserved_region().end(), _reserve_alignment); allocate_metaspace_compressed_klass_ptrs(base, 0); } #endif // _LP64 } // Initialize non-class virtual space list, and its chunk manager: VirtualSpaceList* vsl = new VirtualSpaceList("Non-Class VirtualSpaceList", CommitLimiter::globalLimiter()); VirtualSpaceList::set_vslist_nonclass(vsl); ChunkManager* cm = new ChunkManager("Non-Class ChunkManager", vsl); ChunkManager::set_chunkmanager_nonclass(cm); _tracer = new MetaspaceTracer(); _initialized = true; } void Metaspace::post_initialize() { // TODO do we really need this? Metaspace should not be allocated during VM initialization. assert(RunningCounters::committed_words() == 0, "CHECKECHK"); MetaspaceGC::post_initialize(); } MetaWord* Metaspace::allocate(ClassLoaderData* loader_data, size_t word_size, MetaspaceObj::Type type, TRAPS) { assert(!_frozen, "sanity"); assert(!(DumpSharedSpaces && THREAD->is_VM_thread()), "sanity"); if (HAS_PENDING_EXCEPTION) { assert(false, "Should not allocate with exception pending"); return NULL; // caller does a CHECK_NULL too } assert(loader_data != NULL, "Should never pass around a NULL loader_data. " "ClassLoaderData::the_null_class_loader_data() should have been used."); MetadataType mdtype = (type == MetaspaceObj::ClassType) ? metaspace::ClassType : metaspace::NonClassType; // Try to allocate metadata. MetaWord* result = loader_data->metaspace_non_null()->allocate(word_size, mdtype); if (result == NULL) { tracer()->report_metaspace_allocation_failure(loader_data, word_size, type, mdtype); // Allocation failed. if (is_init_completed()) { // Only start a GC if the bootstrapping has completed. // Try to clean out some heap memory and retry. This can prevent premature // expansion of the metaspace. result = Universe::heap()->satisfy_failed_metadata_allocation(loader_data, word_size, mdtype); } } if (result == NULL) { if (DumpSharedSpaces) { // CDS dumping keeps loading classes, so if we hit an OOM we probably will keep hitting OOM. // We should abort to avoid generating a potentially bad archive. vm_exit_during_cds_dumping(err_msg("Failed allocating metaspace object type %s of size " SIZE_FORMAT ". CDS dump aborted.", MetaspaceObj::type_name(type), word_size * BytesPerWord), err_msg("Please increase MaxMetaspaceSize (currently " SIZE_FORMAT " bytes).", MaxMetaspaceSize)); } report_metadata_oome(loader_data, word_size, type, mdtype, THREAD); assert(HAS_PENDING_EXCEPTION, "sanity"); return NULL; } // Zero initialize. Copy::fill_to_words((HeapWord*)result, word_size, 0); return result; } void Metaspace::report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, MetaspaceObj::Type type, MetadataType mdtype, TRAPS) { tracer()->report_metadata_oom(loader_data, word_size, type, mdtype); // If result is still null, we are out of memory. Log(gc, metaspace, freelist, oom) log; if (log.is_info()) { log.info("Metaspace (%s) allocation failed for size " SIZE_FORMAT, is_class(mdtype) ? "class" : "data", word_size); ResourceMark rm; if (log.is_debug()) { if (loader_data->metaspace_or_null() != NULL) { LogStream ls(log.debug()); loader_data->print_value_on(&ls); } } LogStream ls(log.info()); // In case of an OOM, log out a short but still useful report. MetaspaceUtils::print_basic_report(&ls, 0); } // Which limit did we hit? CompressedClassSpaceSize or MaxMetaspaceSize? bool out_of_compressed_class_space = false; if (is_class(mdtype)) { ClassLoaderMetaspace* metaspace = loader_data->metaspace_non_null(); out_of_compressed_class_space = MetaspaceUtils::committed_bytes(metaspace::ClassType) + // TODO: Okay this is just cheesy. // Of course this may fail and return incorrect results. // Think this over - we need some clean way to remember which limit // exactly we hit during an allocation. Some sort of allocation context structure? align_up(word_size * BytesPerWord, 4 * M) > CompressedClassSpaceSize; } // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support const char* space_string = out_of_compressed_class_space ? "Compressed class space" : "Metaspace"; report_java_out_of_memory(space_string); if (JvmtiExport::should_post_resource_exhausted()) { JvmtiExport::post_resource_exhausted( JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR, space_string); } if (!is_init_completed()) { vm_exit_during_initialization("OutOfMemoryError", space_string); } if (out_of_compressed_class_space) { THROW_OOP(Universe::out_of_memory_error_class_metaspace()); } else { THROW_OOP(Universe::out_of_memory_error_metaspace()); } } void Metaspace::purge() { // Todo } bool Metaspace::contains(const void* ptr) { if (MetaspaceShared::is_in_shared_metaspace(ptr)) { return true; } return contains_non_shared(ptr); } bool Metaspace::contains_non_shared(const void* ptr) { if (using_class_space() && VirtualSpaceList::vslist_class()->contains((MetaWord*)ptr)) { return true; } return VirtualSpaceList::vslist_nonclass()->contains((MetaWord*)ptr); }