| /* |
| * Copyright (c) 2011, 2023, Oracle and/or its affiliates. All rights reserved. |
| * Copyright (c) 2017, 2021 SAP SE. 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 "cds/metaspaceShared.hpp" |
| #include "classfile/classLoaderData.hpp" |
| #include "gc/shared/collectedHeap.hpp" |
| #include "logging/log.hpp" |
| #include "logging/logStream.hpp" |
| #include "memory/classLoaderMetaspace.hpp" |
| #include "memory/metaspace.hpp" |
| #include "memory/metaspaceCriticalAllocation.hpp" |
| #include "memory/metaspace/chunkHeaderPool.hpp" |
| #include "memory/metaspace/chunkManager.hpp" |
| #include "memory/metaspace/commitLimiter.hpp" |
| #include "memory/metaspace/internalStats.hpp" |
| #include "memory/metaspace/metaspaceCommon.hpp" |
| #include "memory/metaspace/metaspaceContext.hpp" |
| #include "memory/metaspace/metaspaceReporter.hpp" |
| #include "memory/metaspace/metaspaceSettings.hpp" |
| #include "memory/metaspace/runningCounters.hpp" |
| #include "memory/metaspace/virtualSpaceList.hpp" |
| #include "memory/metaspaceTracer.hpp" |
| #include "memory/metaspaceStats.hpp" |
| #include "memory/metaspaceUtils.hpp" |
| #include "memory/resourceArea.hpp" |
| #include "memory/universe.hpp" |
| #include "oops/compressedOops.hpp" |
| #include "prims/jvmtiExport.hpp" |
| #include "runtime/atomic.hpp" |
| #include "runtime/globals_extension.hpp" |
| #include "runtime/init.hpp" |
| #include "runtime/java.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::CommitLimiter; |
| using metaspace::MetaspaceContext; |
| using metaspace::MetaspaceReporter; |
| using metaspace::RunningCounters; |
| using metaspace::VirtualSpaceList; |
| |
| size_t MetaspaceUtils::used_words() { |
| return RunningCounters::used_words(); |
| } |
| |
| size_t MetaspaceUtils::used_words(Metaspace::MetadataType mdtype) { |
| return mdtype == Metaspace::ClassType ? RunningCounters::used_words_class() : RunningCounters::used_words_nonclass(); |
| } |
| |
| size_t MetaspaceUtils::reserved_words() { |
| return RunningCounters::reserved_words(); |
| } |
| |
| size_t MetaspaceUtils::reserved_words(Metaspace::MetadataType mdtype) { |
| return mdtype == Metaspace::ClassType ? RunningCounters::reserved_words_class() : RunningCounters::reserved_words_nonclass(); |
| } |
| |
| size_t MetaspaceUtils::committed_words() { |
| return RunningCounters::committed_words(); |
| } |
| |
| size_t MetaspaceUtils::committed_words(Metaspace::MetadataType mdtype) { |
| return mdtype == Metaspace::ClassType ? RunningCounters::committed_words_class() : RunningCounters::committed_words_nonclass(); |
| } |
| |
| // Helper for get_statistics() |
| static void get_values_for(Metaspace::MetadataType mdtype, size_t* reserved, size_t* committed, size_t* used) { |
| #define w2b(x) (x * sizeof(MetaWord)) |
| if (mdtype == Metaspace::ClassType) { |
| *reserved = w2b(RunningCounters::reserved_words_class()); |
| *committed = w2b(RunningCounters::committed_words_class()); |
| *used = w2b(RunningCounters::used_words_class()); |
| } else { |
| *reserved = w2b(RunningCounters::reserved_words_nonclass()); |
| *committed = w2b(RunningCounters::committed_words_nonclass()); |
| *used = w2b(RunningCounters::used_words_nonclass()); |
| } |
| #undef w2b |
| } |
| |
| // Retrieve all statistics in one go; make sure the values are consistent. |
| MetaspaceStats MetaspaceUtils::get_statistics(Metaspace::MetadataType mdtype) { |
| |
| // Consistency: |
| // This function reads three values (reserved, committed, used) from different counters. These counters |
| // may (very rarely) be out of sync. This has been a source for intermittent test errors in the past |
| // (see e.g. JDK-8237872, JDK-8151460). |
| // - reserved and committed counter are updated under protection of Metaspace_lock; an inconsistency |
| // between them can be the result of a dirty read. |
| // - used is an atomic counter updated outside any lock range; there is no way to guarantee |
| // a clean read wrt the other two values. |
| // Reading these values under lock protection would would only help for the first case. Therefore |
| // we don't bother and just re-read several times, then give up and correct the values. |
| |
| size_t r = 0, c = 0, u = 0; // Note: byte values. |
| get_values_for(mdtype, &r, &c, &u); |
| int retries = 10; |
| // If the first retrieval resulted in inconsistent values, retry a bit... |
| while ((r < c || c < u) && --retries >= 0) { |
| get_values_for(mdtype, &r, &c, &u); |
| } |
| if (c < u || r < c) { // still inconsistent. |
| // ... but not endlessly. If we don't get consistent values, correct them on the fly. |
| // The logic here is that we trust the used counter - its an atomic counter and whatever we see |
| // must have been the truth once - and from that we reconstruct a likely set of committed/reserved |
| // values. |
| metaspace::InternalStats::inc_num_inconsistent_stats(); |
| if (c < u) { |
| c = align_up(u, Metaspace::commit_alignment()); |
| } |
| if (r < c) { |
| r = align_up(c, Metaspace::reserve_alignment()); |
| } |
| } |
| return MetaspaceStats(r, c, u); |
| } |
| |
| MetaspaceCombinedStats MetaspaceUtils::get_combined_statistics() { |
| return MetaspaceCombinedStats(get_statistics(Metaspace::ClassType), get_statistics(Metaspace::NonClassType)); |
| } |
| |
| void MetaspaceUtils::print_metaspace_change(const MetaspaceCombinedStats& pre_meta_values) { |
| // Get values now: |
| const MetaspaceCombinedStats meta_values = get_combined_statistics(); |
| |
| // 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())); |
| } |
| } |
| |
| // 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_report(outputStream* out, size_t scale) { |
| const int flags = |
| (int)MetaspaceReporter::Option::ShowLoaders | |
| (int)MetaspaceReporter::Option::BreakDownByChunkType | |
| (int)MetaspaceReporter::Option::ShowClasses; |
| 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. |
| MetaspaceCombinedStats stats = get_combined_statistics(); |
| out->print_cr(" Metaspace " |
| "used " SIZE_FORMAT "K, " |
| "committed " SIZE_FORMAT "K, " |
| "reserved " SIZE_FORMAT "K", |
| stats.used()/K, |
| stats.committed()/K, |
| stats.reserved()/K); |
| |
| if (Metaspace::using_class_space()) { |
| out->print_cr(" class space " |
| "used " SIZE_FORMAT "K, " |
| "committed " SIZE_FORMAT "K, " |
| "reserved " SIZE_FORMAT "K", |
| stats.class_space_stats().used()/K, |
| stats.class_space_stats().committed()/K, |
| stats.class_space_stats().reserved()/K); |
| } |
| } |
| |
| #ifdef ASSERT |
| void MetaspaceUtils::verify() { |
| if (Metaspace::initialized()) { |
| |
| // Verify non-class chunkmanager... |
| ChunkManager* cm = ChunkManager::chunkmanager_nonclass(); |
| cm->verify(); |
| |
| // ... and space list. |
| VirtualSpaceList* vsl = VirtualSpaceList::vslist_nonclass(); |
| vsl->verify(); |
| |
| if (Metaspace::using_class_space()) { |
| // If we use compressed class pointers, verify class chunkmanager... |
| cm = ChunkManager::chunkmanager_class(); |
| cm->verify(); |
| |
| // ... and class spacelist. |
| vsl = VirtualSpaceList::vslist_class(); |
| vsl->verify(); |
| } |
| |
| } |
| } |
| #endif |
| |
| ////////////////////////////////7 |
| // MetaspaceGC methods |
| |
| volatile size_t MetaspaceGC::_capacity_until_GC = 0; |
| uint MetaspaceGC::_shrink_factor = 0; |
| |
| // 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 = Atomic::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::reserve_alignment()); |
| } |
| |
| if (new_value > MaxMetaspaceSize) { |
| if (can_retry != nullptr) { |
| *can_retry = false; |
| } |
| return false; |
| } |
| |
| if (can_retry != nullptr) { |
| *can_retry = true; |
| } |
| size_t prev_value = Atomic::cmpxchg(&_capacity_until_GC, old_capacity_until_GC, new_value); |
| |
| if (old_capacity_until_GC != prev_value) { |
| return false; |
| } |
| |
| if (new_cap_until_GC != nullptr) { |
| *new_cap_until_GC = new_value; |
| } |
| if (old_cap_until_GC != nullptr) { |
| *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(&_capacity_until_GC, v); |
| } |
| |
| 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 successfully 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 ///// |
| |
| const MetaspaceTracer* Metaspace::_tracer = nullptr; |
| |
| bool Metaspace::initialized() { |
| return metaspace::MetaspaceContext::context_nonclass() != nullptr |
| LP64_ONLY(&& (using_class_space() ? Metaspace::class_space_is_initialized() : true)); |
| } |
| |
| #ifdef _LP64 |
| |
| void Metaspace::print_compressed_class_space(outputStream* st) { |
| if (VirtualSpaceList::vslist_class() != nullptr) { |
| MetaWord* base = VirtualSpaceList::vslist_class()->base_of_first_node(); |
| size_t size = VirtualSpaceList::vslist_class()->word_size_of_first_node(); |
| MetaWord* top = base + size; |
| st->print("Compressed class space mapped at: " PTR_FORMAT "-" PTR_FORMAT ", reserved size: " SIZE_FORMAT, |
| p2i(base), p2i(top), (top - base) * BytesPerWord); |
| st->cr(); |
| } |
| } |
| |
| // Given a prereserved space, use that to set up the compressed class space list. |
| void Metaspace::initialize_class_space(ReservedSpace rs) { |
| assert(rs.size() >= CompressedClassSpaceSize, |
| SIZE_FORMAT " != " SIZE_FORMAT, rs.size(), CompressedClassSpaceSize); |
| assert(using_class_space(), "Must be using class space"); |
| |
| assert(rs.size() == CompressedClassSpaceSize, SIZE_FORMAT " != " SIZE_FORMAT, |
| rs.size(), CompressedClassSpaceSize); |
| assert(is_aligned(rs.base(), Metaspace::reserve_alignment()) && |
| is_aligned(rs.size(), Metaspace::reserve_alignment()), |
| "wrong alignment"); |
| |
| MetaspaceContext::initialize_class_space_context(rs); |
| } |
| |
| // Returns true if class space has been setup (initialize_class_space). |
| bool Metaspace::class_space_is_initialized() { |
| return MetaspaceContext::context_class() != nullptr; |
| } |
| |
| // Reserve a range of memory at an address suitable for en/decoding narrow |
| // Klass pointers (see: CompressedClassPointers::is_valid_base()). |
| // The returned address shall both be suitable as a compressed class pointers |
| // base, and aligned to Metaspace::reserve_alignment (which is equal to or a |
| // multiple of allocation granularity). |
| // On error, returns an unreserved space. |
| ReservedSpace Metaspace::reserve_address_space_for_compressed_classes(size_t size) { |
| |
| #if defined(AARCH64) || defined(PPC64) |
| const size_t alignment = Metaspace::reserve_alignment(); |
| |
| // AArch64: Try to align metaspace class space 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. |
| // Additionally, above 32G, ensure the lower LogKlassAlignmentInBytes bits |
| // of the upper 32-bits of the address are zero so we can handle a shift |
| // when decoding. |
| |
| // PPC64: smaller heaps up to 2g will be mapped just below 4g. Then the |
| // attempt to place the compressed class space just after the heap fails on |
| // Linux 4.1.42 and higher because the launcher is loaded at 4g |
| // (ELF_ET_DYN_BASE). In that case we reach here and search the address space |
| // below 32g to get a zerobased CCS. For simplicity we reuse the search |
| // strategy for AARCH64. |
| |
| static const struct { |
| address from; |
| address to; |
| size_t increment; |
| } search_ranges[] = { |
| { (address)(4*G), (address)(32*G), 4*G, }, |
| { (address)(32*G), (address)(1024*G), (4 << LogKlassAlignmentInBytes) * G }, |
| { nullptr, nullptr, 0 } |
| }; |
| |
| // Calculate a list of all possible values for the starting address for the |
| // compressed class space. |
| ResourceMark rm; |
| GrowableArray<address> list(36); |
| for (int i = 0; search_ranges[i].from != nullptr; i ++) { |
| address a = search_ranges[i].from; |
| assert(CompressedKlassPointers::is_valid_base(a), "Sanity"); |
| while (a < search_ranges[i].to) { |
| list.append(a); |
| a += search_ranges[i].increment; |
| } |
| } |
| |
| int len = list.length(); |
| int r = 0; |
| if (!DumpSharedSpaces) { |
| // Starting from a random position in the list. If the address cannot be reserved |
| // (the OS already assigned it for something else), go to the next position, wrapping |
| // around if necessary, until we exhaust all the items. |
| os::init_random((int)os::javaTimeNanos()); |
| r = ABS(os::random()) % len; |
| assert(r >= 0, "must be"); |
| log_info(metaspace)("Randomizing compressed class space: start from %d out of %d locations", |
| r, len); |
| } |
| for (int i = 0; i < len; i++) { |
| assert((i + r) >= 0, "should never underflow because len is small integer"); |
| address a = list.at((i + r) % len); |
| ReservedSpace rs(size, Metaspace::reserve_alignment(), |
| os::vm_page_size(), (char*)a); |
| if (rs.is_reserved()) { |
| assert(a == (address)rs.base(), "Sanity"); |
| return rs; |
| } |
| } |
| #endif // defined(AARCH64) || defined(PPC64) |
| |
| #ifdef AARCH64 |
| // Note: on AARCH64, if the code above does not find any good placement, we |
| // have no recourse. We return an empty space and the VM will exit. |
| return ReservedSpace(); |
| #else |
| // Default implementation: Just reserve anywhere. |
| return ReservedSpace(size, Metaspace::reserve_alignment(), os::vm_page_size(), (char*)nullptr); |
| #endif // AARCH64 |
| } |
| |
| #endif // _LP64 |
| |
| size_t Metaspace::reserve_alignment_words() { |
| return metaspace::Settings::virtual_space_node_reserve_alignment_words(); |
| } |
| |
| size_t Metaspace::commit_alignment_words() { |
| return metaspace::Settings::commit_granule_words(); |
| } |
| |
| void Metaspace::ergo_initialize() { |
| |
| // Must happen before using any setting from Settings::--- |
| metaspace::Settings::ergo_initialize(); |
| |
| // MaxMetaspaceSize and CompressedClassSpaceSize: |
| // |
| // MaxMetaspaceSize is the maximum size, in bytes, of memory we are allowed |
| // to commit for the Metaspace. |
| // It is just a number; a limit we compare against before committing. It |
| // does not have to be aligned to anything. |
| // It gets used as compare value before attempting to increase the metaspace |
| // commit charge. It defaults to max_uintx (unlimited). |
| // |
| // CompressedClassSpaceSize is the size, in bytes, of the address range we |
| // pre-reserve for the compressed class space (if we use class space). |
| // This size has to be aligned to the metaspace reserve alignment (to the |
| // size of a root chunk). It gets aligned up from whatever value the caller |
| // gave us to the next multiple of root chunk size. |
| // |
| // Note: Strictly speaking MaxMetaspaceSize and CompressedClassSpaceSize have |
| // very little to do with each other. The notion often encountered: |
| // MaxMetaspaceSize = CompressedClassSpaceSize + <non-class metadata size> |
| // is subtly wrong: MaxMetaspaceSize can besmaller than CompressedClassSpaceSize, |
| // in which case we just would not be able to fully commit the class space range. |
| // |
| // We still adjust CompressedClassSpaceSize to reasonable limits, mainly to |
| // save on reserved space, and to make ergnonomics less confusing. |
| |
| MaxMetaspaceSize = MAX2(MaxMetaspaceSize, commit_alignment()); |
| |
| if (UseCompressedClassPointers) { |
| // Let CCS size not be larger than 80% of MaxMetaspaceSize. Note that is |
| // grossly over-dimensioned for most usage scenarios; typical ratio of |
| // class space : non class space usage is about 1:6. With many small classes, |
| // it can get as low as 1:2. It is not a big deal though since ccs is only |
| // reserved and will be committed on demand only. |
| size_t max_ccs_size = MaxMetaspaceSize * 0.8; |
| size_t adjusted_ccs_size = MIN2(CompressedClassSpaceSize, max_ccs_size); |
| |
| // CCS must be aligned to root chunk size, and be at least the size of one |
| // root chunk. |
| adjusted_ccs_size = align_up(adjusted_ccs_size, reserve_alignment()); |
| adjusted_ccs_size = MAX2(adjusted_ccs_size, reserve_alignment()); |
| |
| // Note: re-adjusting may have us left with a CompressedClassSpaceSize |
| // larger than MaxMetaspaceSize for very small values of MaxMetaspaceSize. |
| // Lets just live with that, its not a big deal. |
| |
| if (adjusted_ccs_size != CompressedClassSpaceSize) { |
| FLAG_SET_ERGO(CompressedClassSpaceSize, adjusted_ccs_size); |
| log_info(metaspace)("Setting CompressedClassSpaceSize to " SIZE_FORMAT ".", |
| CompressedClassSpaceSize); |
| } |
| } |
| |
| // Set MetaspaceSize, MinMetaspaceExpansion and MaxMetaspaceExpansion |
| 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()); |
| |
| } |
| |
| void Metaspace::global_initialize() { |
| MetaspaceGC::initialize(); // <- since we do not prealloc init chunks anymore is this still needed? |
| |
| metaspace::ChunkHeaderPool::initialize(); |
| |
| if (DumpSharedSpaces) { |
| assert(!UseSharedSpaces, "sanity"); |
| MetaspaceShared::initialize_for_static_dump(); |
| } |
| |
| // If UseCompressedClassPointers=1, we have two cases: |
| // a) if CDS is active (runtime, Xshare=on), it will create the class space |
| // for us, initialize it and set up CompressedKlassPointers encoding. |
| // Class space will be reserved above the mapped archives. |
| // b) if CDS either deactivated (Xshare=off) or a static dump is to be done (Xshare:dump), |
| // we will create the class space on our own. It will be placed above the java heap, |
| // since we assume it has been placed in low |
| // address regions. We may rethink this (see JDK-8244943). Failing that, |
| // it will be placed anywhere. |
| |
| #if INCLUDE_CDS |
| // case (a) |
| if (UseSharedSpaces) { |
| if (!FLAG_IS_DEFAULT(CompressedClassSpaceBaseAddress)) { |
| log_warning(metaspace)("CDS active - ignoring CompressedClassSpaceBaseAddress."); |
| } |
| MetaspaceShared::initialize_runtime_shared_and_meta_spaces(); |
| // If any of the archived space fails to map, UseSharedSpaces |
| // is reset to false. |
| } |
| #endif // INCLUDE_CDS |
| |
| #ifdef _LP64 |
| |
| if (using_class_space() && !class_space_is_initialized()) { |
| assert(!UseSharedSpaces, "CDS archive is not mapped at this point"); |
| |
| // case (b) (No CDS) |
| ReservedSpace rs; |
| const size_t size = align_up(CompressedClassSpaceSize, Metaspace::reserve_alignment()); |
| address base = nullptr; |
| |
| // If CompressedClassSpaceBaseAddress is set, we attempt to force-map class space to |
| // the given address. This is a debug-only feature aiding tests. Due to the ASLR lottery |
| // this may fail, in which case the VM will exit after printing an appropriate message. |
| // Tests using this switch should cope with that. |
| if (CompressedClassSpaceBaseAddress != 0) { |
| base = (address)CompressedClassSpaceBaseAddress; |
| if (!is_aligned(base, Metaspace::reserve_alignment())) { |
| vm_exit_during_initialization( |
| err_msg("CompressedClassSpaceBaseAddress=" PTR_FORMAT " invalid " |
| "(must be aligned to " SIZE_FORMAT_X ").", |
| CompressedClassSpaceBaseAddress, Metaspace::reserve_alignment())); |
| } |
| rs = ReservedSpace(size, Metaspace::reserve_alignment(), |
| os::vm_page_size() /* large */, (char*)base); |
| if (rs.is_reserved()) { |
| log_info(metaspace)("Successfully forced class space address to " PTR_FORMAT, p2i(base)); |
| } else { |
| vm_exit_during_initialization( |
| err_msg("CompressedClassSpaceBaseAddress=" PTR_FORMAT " given, but reserving class space failed.", |
| CompressedClassSpaceBaseAddress)); |
| } |
| } |
| |
| if (!rs.is_reserved()) { |
| // If UseCompressedOops=1 and the java heap has been placed in coops-friendly |
| // territory, i.e. its base is under 32G, then we attempt to place ccs |
| // right above the java heap. |
| // Otherwise the lower 32G are still free. We try to place ccs at the lowest |
| // allowed mapping address. |
| base = (UseCompressedOops && (uint64_t)CompressedOops::base() < OopEncodingHeapMax) ? |
| CompressedOops::end() : (address)HeapBaseMinAddress; |
| base = align_up(base, Metaspace::reserve_alignment()); |
| |
| if (base != nullptr) { |
| if (CompressedKlassPointers::is_valid_base(base)) { |
| rs = ReservedSpace(size, Metaspace::reserve_alignment(), |
| os::vm_page_size(), (char*)base); |
| } |
| } |
| } |
| |
| // ...failing that, reserve anywhere, but let platform do optimized placement: |
| if (!rs.is_reserved()) { |
| rs = Metaspace::reserve_address_space_for_compressed_classes(size); |
| } |
| |
| // ...failing that, give up. |
| if (!rs.is_reserved()) { |
| vm_exit_during_initialization( |
| err_msg("Could not allocate compressed class space: " SIZE_FORMAT " bytes", |
| CompressedClassSpaceSize)); |
| } |
| |
| // Mark class space as such |
| MemTracker::record_virtual_memory_type((address)rs.base(), mtClass); |
| |
| // Initialize space |
| Metaspace::initialize_class_space(rs); |
| |
| // Set up compressed class pointer encoding. |
| CompressedKlassPointers::initialize((address)rs.base(), rs.size()); |
| } |
| |
| #endif |
| |
| // Initialize non-class virtual space list, and its chunk manager: |
| MetaspaceContext::initialize_nonclass_space_context(); |
| |
| _tracer = new MetaspaceTracer(); |
| |
| // We must prevent the very first address of the ccs from being used to store |
| // metadata, since that address would translate to a narrow pointer of 0, and the |
| // VM does not distinguish between "narrow 0 as in null" and "narrow 0 as in start |
| // of ccs". |
| // Before Elastic Metaspace that did not happen due to the fact that every Metachunk |
| // had a header and therefore could not allocate anything at offset 0. |
| #ifdef _LP64 |
| if (using_class_space()) { |
| // The simplest way to fix this is to allocate a tiny dummy chunk right at the |
| // start of ccs and do not use it for anything. |
| MetaspaceContext::context_class()->cm()->get_chunk(metaspace::chunklevel::HIGHEST_CHUNK_LEVEL); |
| } |
| #endif |
| |
| #ifdef _LP64 |
| if (UseCompressedClassPointers) { |
| // Note: "cds" would be a better fit but keep this for backward compatibility. |
| LogTarget(Info, gc, metaspace) lt; |
| if (lt.is_enabled()) { |
| ResourceMark rm; |
| LogStream ls(lt); |
| CDS_ONLY(MetaspaceShared::print_on(&ls);) |
| Metaspace::print_compressed_class_space(&ls); |
| CompressedKlassPointers::print_mode(&ls); |
| } |
| } |
| #endif |
| |
| } |
| |
| void Metaspace::post_initialize() { |
| MetaspaceGC::post_initialize(); |
| } |
| |
| size_t Metaspace::max_allocation_word_size() { |
| return metaspace::chunklevel::MAX_CHUNK_WORD_SIZE; |
| } |
| |
| // This version of Metaspace::allocate does not throw OOM but simply returns null, and |
| // is suitable for calling from non-Java threads. |
| // Callers are responsible for checking null. |
| MetaWord* Metaspace::allocate(ClassLoaderData* loader_data, size_t word_size, |
| MetaspaceObj::Type type) { |
| assert(word_size <= Metaspace::max_allocation_word_size(), |
| "allocation size too large (" SIZE_FORMAT ")", word_size); |
| |
| assert(loader_data != nullptr, "Should never pass around a null loader_data. " |
| "ClassLoaderData::the_null_class_loader_data() should have been used."); |
| |
| // Deal with concurrent unloading failed allocation starvation |
| MetaspaceCriticalAllocation::block_if_concurrent_purge(); |
| |
| MetadataType mdtype = (type == MetaspaceObj::ClassType) ? ClassType : NonClassType; |
| |
| // Try to allocate metadata. |
| MetaWord* result = loader_data->metaspace_non_null()->allocate(word_size, mdtype); |
| |
| if (result != nullptr) { |
| // Zero initialize. |
| Copy::fill_to_words((HeapWord*)result, word_size, 0); |
| |
| log_trace(metaspace)("Metaspace::allocate: type %d return " PTR_FORMAT ".", (int)type, p2i(result)); |
| } |
| |
| return result; |
| } |
| |
| MetaWord* Metaspace::allocate(ClassLoaderData* loader_data, size_t word_size, |
| MetaspaceObj::Type type, TRAPS) { |
| |
| if (HAS_PENDING_EXCEPTION) { |
| assert(false, "Should not allocate with exception pending"); |
| return nullptr; // caller does a CHECK_NULL too |
| } |
| |
| MetaWord* result = allocate(loader_data, word_size, type); |
| |
| if (result == nullptr) { |
| MetadataType mdtype = (type == MetaspaceObj::ClassType) ? ClassType : NonClassType; |
| 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 == nullptr) { |
| report_metadata_oome(loader_data, word_size, type, mdtype, THREAD); |
| assert(HAS_PENDING_EXCEPTION, "sanity"); |
| return nullptr; |
| } |
| |
| // Zero initialize. |
| Copy::fill_to_words((HeapWord*)result, word_size, 0); |
| |
| log_trace(metaspace)("Metaspace::allocate: type %d return " PTR_FORMAT ".", (int)type, p2i(result)); |
| } |
| |
| 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_space_allocation(mdtype) ? "class" : "data", word_size); |
| ResourceMark rm; |
| if (log.is_debug()) { |
| if (loader_data->metaspace_or_null() != nullptr) { |
| 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); |
| } |
| |
| bool out_of_compressed_class_space = false; |
| if (is_class_space_allocation(mdtype)) { |
| ClassLoaderMetaspace* metaspace = loader_data->metaspace_non_null(); |
| out_of_compressed_class_space = |
| MetaspaceUtils::committed_bytes(Metaspace::ClassType) + |
| 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()); |
| } |
| } |
| |
| const char* Metaspace::metadata_type_name(Metaspace::MetadataType mdtype) { |
| switch (mdtype) { |
| case Metaspace::ClassType: return "Class"; |
| case Metaspace::NonClassType: return "Metadata"; |
| default: |
| assert(false, "Got bad mdtype: %d", (int) mdtype); |
| return nullptr; |
| } |
| } |
| |
| void Metaspace::purge(bool classes_unloaded) { |
| // The MetaspaceCritical_lock is used by a concurrent GC to block out concurrent metaspace |
| // allocations, that would starve critical metaspace allocations, that are about to throw |
| // OOM if they fail; they need precedence for correctness. |
| MutexLocker ml(MetaspaceCritical_lock, Mutex::_no_safepoint_check_flag); |
| if (classes_unloaded) { |
| ChunkManager* cm = ChunkManager::chunkmanager_nonclass(); |
| if (cm != nullptr) { |
| cm->purge(); |
| } |
| if (using_class_space()) { |
| cm = ChunkManager::chunkmanager_class(); |
| if (cm != nullptr) { |
| cm->purge(); |
| } |
| } |
| } |
| |
| // Try to satisfy queued metaspace allocation requests. |
| // |
| // It might seem unnecessary to try to process allocation requests if no |
| // classes have been unloaded. However, this call is required for the code |
| // in MetaspaceCriticalAllocation::try_allocate_critical to work. |
| MetaspaceCriticalAllocation::process(); |
| } |
| |
| 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); |
| } |
