jdk8-mips64-public/hotspot: src/share/vm/services/memTracker.cpp@833b0f92429a (annotated)

src/share/vm/services/memTracker.cpp@833b0f92429a (annotated)

src/share/vm/services/memTracker.cpp

Wed, 27 Aug 2014 08:19:12 -0400

author: zgu
date: Wed, 27 Aug 2014 08:19:12 -0400
changeset 7074: 833b0f92429a
parent 6911: ce8f6bb717c9
child 7077: 36c9011aaead
permissions: -rw-r--r--

8046598: Scalable Native memory tracking development
Summary: Enhance scalability of native memory tracking
Reviewed-by: coleenp, ctornqvi, gtriantafill

 /*
  * Copyright (c) 2012, 2014, 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 "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;
 NativeCallStack emptyStack(0, false);
 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];
   char nmt_option[64];
   jio_snprintf(buf, sizeof(buf), "NMT_LEVEL_%d", os::current_process_id());
   if (os::getenv(buf, nmt_option, sizeof(nmt_option))) {
     if (strcmp(nmt_option, "summary") == 0) {
       level = NMT_summary;
     } else if (strcmp(nmt_option, "detail") == 0) {
 #if PLATFORM_NATIVE_STACK_WALKING_SUPPORTED
       level = NMT_detail;
 #else
       level = NMT_summary;
 #endif // PLATFORM_NATIVE_STACK_WALKING_SUPPORTED
     } 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);
   }
   if (!MallocTracker::initialize(level) ||
       !VirtualMemoryTracker::initialize(level)) {
     level = NMT_off;
   }
   return level;
 }
 void MemTracker::init() {
   if (tracking_level() >= NMT_summary) {
     _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 !PLATFORM_NATIVE_STACK_WALKING_SUPPORTED
       jio_fprintf(defaultStream::error_stream(),
         "NMT detail is not supported on this platform.  Using NMT summary instead.\n");
     if (MemTracker::tracking_level() != NMT_summary) {
     return false;
   }
 #else
     if (MemTracker::tracking_level() != NMT_detail) {
       return false;
     }
 #endif
   } 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();
   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);
     if (level == NMT_minimal) _baseline.reset();
   } else {
     VirtualMemoryTracker::transition(current_level, level);
     MallocTracker::transition(current_level, level);
     _tracking_level = level;
     // Make _tracking_level visible immediately.
     OrderAccess::fence();
   }
   return true;
 }
 void MemTracker::final_report(outputStream* output) {
   assert(output != NULL, "No output stream");
   if (tracking_level() >= NMT_summary) {
     MallocMemorySnapshot* malloc_memory_snapshot =
       MallocMemorySummary::as_snapshot();
     malloc_memory_snapshot->make_adjustment();
     VirtualMemorySnapshot* virtual_memory_snapshot =
       VirtualMemorySummary::as_snapshot();
     MemSummaryReporter rptr(malloc_memory_snapshot,
       virtual_memory_snapshot, output);
     rptr.report();
     // shutdown NMT, the data no longer accurate
     shutdown();
   }
 }
 // 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 at(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);
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/services/memTracker.cpp@833b0f92429a (annotated)

src/share/vm/services/memTracker.cpp