| /* |
| * Copyright (c) 2012, 2017, 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 "prims/jvm.h" |
| #include "runtime/mutex.hpp" |
| #include "services/memBaseline.hpp" |
| #include "services/memReporter.hpp" |
| #include "services/mallocTracker.inline.hpp" |
| #include "services/memTracker.hpp" |
| #include "utilities/defaultStream.hpp" |
| |
| #ifdef SOLARIS |
| volatile bool NMT_stack_walkable = false; |
| #else |
| volatile bool NMT_stack_walkable = true; |
| #endif |
| |
| volatile NMT_TrackingLevel MemTracker::_tracking_level = NMT_unknown; |
| NMT_TrackingLevel MemTracker::_cmdline_tracking_level = NMT_unknown; |
| |
| MemBaseline MemTracker::_baseline; |
| Mutex* MemTracker::_query_lock = NULL; |
| bool MemTracker::_is_nmt_env_valid = true; |
| |
| |
| NMT_TrackingLevel MemTracker::init_tracking_level() { |
| NMT_TrackingLevel level = NMT_off; |
| char buf[64]; |
| jio_snprintf(buf, sizeof(buf), "NMT_LEVEL_%d", os::current_process_id()); |
| const char *nmt_option = ::getenv(buf); |
| if (nmt_option != NULL) { |
| if (strcmp(nmt_option, "summary") == 0) { |
| level = NMT_summary; |
| } else if (strcmp(nmt_option, "detail") == 0) { |
| level = NMT_detail; |
| } else if (strcmp(nmt_option, "off") != 0) { |
| // The option value is invalid |
| _is_nmt_env_valid = false; |
| } |
| |
| // Remove the environment variable to avoid leaking to child processes |
| os::unsetenv(buf); |
| } |
| |
| // Construct NativeCallStack::EMPTY_STACK. It may get constructed twice, |
| // but it is benign, the results are the same. |
| ::new ((void*)&NativeCallStack::EMPTY_STACK) NativeCallStack(0, false); |
| |
| if (!MallocTracker::initialize(level) || |
| !VirtualMemoryTracker::initialize(level)) { |
| level = NMT_off; |
| } |
| return level; |
| } |
| |
| void MemTracker::init() { |
| NMT_TrackingLevel level = tracking_level(); |
| if (level >= NMT_summary) { |
| if (!VirtualMemoryTracker::late_initialize(level)) { |
| shutdown(); |
| return; |
| } |
| _query_lock = new (std::nothrow) Mutex(Monitor::max_nonleaf, "NMT_queryLock"); |
| // Already OOM. It is unlikely, but still have to handle it. |
| if (_query_lock == NULL) { |
| shutdown(); |
| } |
| } |
| } |
| |
| bool MemTracker::check_launcher_nmt_support(const char* value) { |
| if (strcmp(value, "=detail") == 0) { |
| if (MemTracker::tracking_level() != NMT_detail) { |
| return false; |
| } |
| } else if (strcmp(value, "=summary") == 0) { |
| if (MemTracker::tracking_level() != NMT_summary) { |
| return false; |
| } |
| } else if (strcmp(value, "=off") == 0) { |
| if (MemTracker::tracking_level() != NMT_off) { |
| return false; |
| } |
| } else { |
| _is_nmt_env_valid = false; |
| } |
| |
| return true; |
| } |
| |
| bool MemTracker::verify_nmt_option() { |
| return _is_nmt_env_valid; |
| } |
| |
| void* MemTracker::malloc_base(void* memblock) { |
| return MallocTracker::get_base(memblock); |
| } |
| |
| void Tracker::record(address addr, size_t size) { |
| if (MemTracker::tracking_level() < NMT_summary) return; |
| switch(_type) { |
| case uncommit: |
| VirtualMemoryTracker::remove_uncommitted_region(addr, size); |
| break; |
| case release: |
| VirtualMemoryTracker::remove_released_region(addr, size); |
| break; |
| default: |
| ShouldNotReachHere(); |
| } |
| } |
| |
| |
| // Shutdown can only be issued via JCmd, and NMT JCmd is serialized by lock |
| void MemTracker::shutdown() { |
| // We can only shutdown NMT to minimal tracking level if it is ever on. |
| if (tracking_level () > NMT_minimal) { |
| transition_to(NMT_minimal); |
| } |
| } |
| |
| bool MemTracker::transition_to(NMT_TrackingLevel level) { |
| NMT_TrackingLevel current_level = tracking_level(); |
| |
| assert(level != NMT_off || current_level == NMT_off, "Cannot transition NMT to off"); |
| |
| if (current_level == level) { |
| return true; |
| } else if (current_level > level) { |
| // Downgrade tracking level, we want to lower the tracking level first |
| _tracking_level = level; |
| // Make _tracking_level visible immediately. |
| OrderAccess::fence(); |
| VirtualMemoryTracker::transition(current_level, level); |
| MallocTracker::transition(current_level, level); |
| } else { |
| // Upgrading tracking level is not supported and has never been supported. |
| // Allocating and deallocating malloc tracking structures is not thread safe and |
| // leads to inconsistencies unless a lot coarser locks are added. |
| } |
| return true; |
| } |
| |
| void MemTracker::report(bool summary_only, outputStream* output) { |
| assert(output != NULL, "No output stream"); |
| MemBaseline baseline; |
| if (baseline.baseline(summary_only)) { |
| if (summary_only) { |
| MemSummaryReporter rpt(baseline, output); |
| rpt.report(); |
| } else { |
| MemDetailReporter rpt(baseline, output); |
| rpt.report(); |
| } |
| } |
| } |
| |
| // This is a walker to gather malloc site hashtable statistics, |
| // the result is used for tuning. |
| class StatisticsWalker : public MallocSiteWalker { |
| private: |
| enum Threshold { |
| // aggregates statistics over this threshold into one |
| // line item. |
| report_threshold = 20 |
| }; |
| |
| private: |
| // Number of allocation sites that have all memory freed |
| int _empty_entries; |
| // Total number of allocation sites, include empty sites |
| int _total_entries; |
| // Number of captured call stack distribution |
| int _stack_depth_distribution[NMT_TrackingStackDepth]; |
| // Hash distribution |
| int _hash_distribution[report_threshold]; |
| // Number of hash buckets that have entries over the threshold |
| int _bucket_over_threshold; |
| |
| // The hash bucket that walker is currently walking |
| int _current_hash_bucket; |
| // The length of current hash bucket |
| int _current_bucket_length; |
| // Number of hash buckets that are not empty |
| int _used_buckets; |
| // Longest hash bucket length |
| int _longest_bucket_length; |
| |
| public: |
| StatisticsWalker() : _empty_entries(0), _total_entries(0) { |
| int index = 0; |
| for (index = 0; index < NMT_TrackingStackDepth; index ++) { |
| _stack_depth_distribution[index] = 0; |
| } |
| for (index = 0; index < report_threshold; index ++) { |
| _hash_distribution[index] = 0; |
| } |
| _bucket_over_threshold = 0; |
| _longest_bucket_length = 0; |
| _current_hash_bucket = -1; |
| _current_bucket_length = 0; |
| _used_buckets = 0; |
| } |
| |
| virtual bool do_malloc_site(const MallocSite* e) { |
| if (e->size() == 0) _empty_entries ++; |
| _total_entries ++; |
| |
| // stack depth distrubution |
| int frames = e->call_stack()->frames(); |
| _stack_depth_distribution[frames - 1] ++; |
| |
| // hash distribution |
| int hash_bucket = e->hash() % MallocSiteTable::hash_buckets(); |
| if (_current_hash_bucket == -1) { |
| _current_hash_bucket = hash_bucket; |
| _current_bucket_length = 1; |
| } else if (_current_hash_bucket == hash_bucket) { |
| _current_bucket_length ++; |
| } else { |
| record_bucket_length(_current_bucket_length); |
| _current_hash_bucket = hash_bucket; |
| _current_bucket_length = 1; |
| } |
| return true; |
| } |
| |
| // walk completed |
| void completed() { |
| record_bucket_length(_current_bucket_length); |
| } |
| |
| void report_statistics(outputStream* out) { |
| int index; |
| out->print_cr("Malloc allocation site table:"); |
| out->print_cr("\tTotal entries: %d", _total_entries); |
| out->print_cr("\tEmpty entries: %d (%2.2f%%)", _empty_entries, ((float)_empty_entries * 100) / _total_entries); |
| out->print_cr(" "); |
| out->print_cr("Hash distribution:"); |
| if (_used_buckets < MallocSiteTable::hash_buckets()) { |
| out->print_cr("empty bucket: %d", (MallocSiteTable::hash_buckets() - _used_buckets)); |
| } |
| for (index = 0; index < report_threshold; index ++) { |
| if (_hash_distribution[index] != 0) { |
| if (index == 0) { |
| out->print_cr(" %d entry: %d", 1, _hash_distribution[0]); |
| } else if (index < 9) { // single digit |
| out->print_cr(" %d entries: %d", (index + 1), _hash_distribution[index]); |
| } else { |
| out->print_cr(" %d entries: %d", (index + 1), _hash_distribution[index]); |
| } |
| } |
| } |
| if (_bucket_over_threshold > 0) { |
| out->print_cr(" >%d entries: %d", report_threshold, _bucket_over_threshold); |
| } |
| out->print_cr("most entries: %d", _longest_bucket_length); |
| out->print_cr(" "); |
| out->print_cr("Call stack depth distribution:"); |
| for (index = 0; index < NMT_TrackingStackDepth; index ++) { |
| if (_stack_depth_distribution[index] > 0) { |
| out->print_cr("\t%d: %d", index + 1, _stack_depth_distribution[index]); |
| } |
| } |
| } |
| |
| private: |
| void record_bucket_length(int length) { |
| _used_buckets ++; |
| if (length <= report_threshold) { |
| _hash_distribution[length - 1] ++; |
| } else { |
| _bucket_over_threshold ++; |
| } |
| _longest_bucket_length = MAX2(_longest_bucket_length, length); |
| } |
| }; |
| |
| |
| void MemTracker::tuning_statistics(outputStream* out) { |
| // NMT statistics |
| StatisticsWalker walker; |
| MallocSiteTable::walk_malloc_site(&walker); |
| walker.completed(); |
| |
| out->print_cr("Native Memory Tracking Statistics:"); |
| out->print_cr("Malloc allocation site table size: %d", MallocSiteTable::hash_buckets()); |
| out->print_cr(" Tracking stack depth: %d", NMT_TrackingStackDepth); |
| NOT_PRODUCT(out->print_cr("Peak concurrent access: %d", MallocSiteTable::access_peak_count());) |
| out->print_cr(" "); |
| walker.report_statistics(out); |
| } |