1 /*
   2  * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 
  26 #include "precompiled.hpp"
  27 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
  28 #include "gc_implementation/g1/g1GCPhaseTimes.hpp"
  29 #include "gc_implementation/g1/g1Log.hpp"
  30 
  31 // Helper class for avoiding interleaved logging
  32 class LineBuffer: public StackObj {
  33 
  34 private:
  35   static const int BUFFER_LEN = 1024;
  36   static const int INDENT_CHARS = 3;
  37   char _buffer[BUFFER_LEN];
  38   int _indent_level;
  39   int _cur;
  40 
  41   void vappend(const char* format, va_list ap) {
  42     int res = vsnprintf(&_buffer[_cur], BUFFER_LEN - _cur, format, ap);
  43     if (res != -1) {
  44       _cur += res;
  45     } else {
  46       DEBUG_ONLY(warning("buffer too small in LineBuffer");)
  47       _buffer[BUFFER_LEN -1] = 0;
  48       _cur = BUFFER_LEN; // vsnprintf above should not add to _buffer if we are called again
  49     }
  50   }
  51 
  52 public:
  53   explicit LineBuffer(int indent_level): _indent_level(indent_level), _cur(0) {
  54     for (; (_cur < BUFFER_LEN && _cur < (_indent_level * INDENT_CHARS)); _cur++) {
  55       _buffer[_cur] = ' ';
  56     }
  57   }
  58 
  59 #ifndef PRODUCT
  60   ~LineBuffer() {
  61     assert(_cur == _indent_level * INDENT_CHARS, "pending data in buffer - append_and_print_cr() not called?");
  62   }
  63 #endif
  64 
  65   void append(const char* format, ...) {
  66     va_list ap;
  67     va_start(ap, format);
  68     vappend(format, ap);
  69     va_end(ap);
  70   }
  71 
  72   void append_and_print_cr(const char* format, ...) {
  73     va_list ap;
  74     va_start(ap, format);
  75     vappend(format, ap);
  76     va_end(ap);
  77     gclog_or_tty->print_cr("%s", _buffer);
  78     _cur = _indent_level * INDENT_CHARS;
  79   }
  80 };
  81 
  82 G1GCPhaseTimes::G1GCPhaseTimes(uint max_gc_threads) :
  83   _max_gc_threads(max_gc_threads),
  84   _min_clear_cc_time_ms(-1.0),
  85   _max_clear_cc_time_ms(-1.0),
  86   _cur_clear_cc_time_ms(0.0),
  87   _cum_clear_cc_time_ms(0.0),
  88   _num_cc_clears(0L)
  89 {
  90   assert(max_gc_threads > 0, "Must have some GC threads");
  91   _par_last_gc_worker_start_times_ms = new double[_max_gc_threads];
  92   _par_last_ext_root_scan_times_ms = new double[_max_gc_threads];
  93   _par_last_satb_filtering_times_ms = new double[_max_gc_threads];
  94   _par_last_update_rs_times_ms = new double[_max_gc_threads];
  95   _par_last_update_rs_processed_buffers = new double[_max_gc_threads];
  96   _par_last_scan_rs_times_ms = new double[_max_gc_threads];
  97   _par_last_obj_copy_times_ms = new double[_max_gc_threads];
  98   _par_last_termination_times_ms = new double[_max_gc_threads];
  99   _par_last_termination_attempts = new double[_max_gc_threads];
 100   _par_last_gc_worker_end_times_ms = new double[_max_gc_threads];
 101   _par_last_gc_worker_times_ms = new double[_max_gc_threads];
 102   _par_last_gc_worker_other_times_ms = new double[_max_gc_threads];
 103 }
 104 
 105 void G1GCPhaseTimes::note_gc_start(double pause_start_time_sec, uint active_gc_threads,
 106   bool is_young_gc, bool is_initial_mark_gc, GCCause::Cause gc_cause) {
 107   assert(active_gc_threads > 0, "The number of threads must be > 0");
 108   assert(active_gc_threads <= _max_gc_threads, "The number of active threads must be <= the max nubmer of threads");
 109   _active_gc_threads = active_gc_threads;
 110   _pause_start_time_sec = pause_start_time_sec;
 111   _is_young_gc = is_young_gc;
 112   _is_initial_mark_gc = is_initial_mark_gc;
 113   _gc_cause = gc_cause;
 114 
 115 #ifdef ASSERT
 116   // initialise the timing data to something well known so that we can spot
 117   // if something is not set properly
 118 
 119   for (uint i = 0; i < _max_gc_threads; ++i) {
 120     _par_last_gc_worker_start_times_ms[i] = -1234.0;
 121     _par_last_ext_root_scan_times_ms[i] = -1234.0;
 122     _par_last_satb_filtering_times_ms[i] = -1234.0;
 123     _par_last_update_rs_times_ms[i] = -1234.0;
 124     _par_last_update_rs_processed_buffers[i] = -1234.0;
 125     _par_last_scan_rs_times_ms[i] = -1234.0;
 126     _par_last_obj_copy_times_ms[i] = -1234.0;
 127     _par_last_termination_times_ms[i] = -1234.0;
 128     _par_last_termination_attempts[i] = -1234.0;
 129     _par_last_gc_worker_end_times_ms[i] = -1234.0;
 130     _par_last_gc_worker_times_ms[i] = -1234.0;
 131     _par_last_gc_worker_other_times_ms[i] = -1234.0;
 132   }
 133 #endif
 134 }
 135 
 136 void G1GCPhaseTimes::note_gc_end(double pause_end_time_sec) {
 137   if (G1Log::fine()) {
 138     double pause_time_ms = (pause_end_time_sec - _pause_start_time_sec) * MILLIUNITS;
 139 
 140     for (uint i = 0; i < _active_gc_threads; i++) {
 141       _par_last_gc_worker_times_ms[i] = _par_last_gc_worker_end_times_ms[i] -
 142         _par_last_gc_worker_start_times_ms[i];
 143 
 144       double worker_known_time = _par_last_ext_root_scan_times_ms[i] +
 145         _par_last_satb_filtering_times_ms[i] +
 146         _par_last_update_rs_times_ms[i] +
 147         _par_last_scan_rs_times_ms[i] +
 148         _par_last_obj_copy_times_ms[i] +
 149         _par_last_termination_times_ms[i];
 150 
 151       _par_last_gc_worker_other_times_ms[i] = _par_last_gc_worker_times_ms[i] -
 152         worker_known_time;
 153     }
 154 
 155     print(pause_time_ms);
 156   }
 157 
 158 }
 159 
 160 void G1GCPhaseTimes::print_par_stats(int level,
 161                                         const char* str,
 162                                         double* data,
 163                                         bool showDecimals) {
 164   double min = data[0], max = data[0];
 165   double total = 0.0;
 166   LineBuffer buf(level);
 167   buf.append("[%s (ms):", str);
 168   for (uint i = 0; i < _active_gc_threads; ++i) {
 169     double val = data[i];
 170     if (val < min)
 171       min = val;
 172     if (val > max)
 173       max = val;
 174     total += val;
 175     if (G1Log::finest()) {
 176       if (showDecimals) {
 177         buf.append("  %.1lf", val);
 178       } else {
 179         buf.append("  %d", (int)val);
 180       }
 181     }
 182   }
 183 
 184   if (G1Log::finest()) {
 185     buf.append_and_print_cr("");
 186   }
 187   double avg = total / (double) _active_gc_threads;
 188   if (showDecimals) {
 189     buf.append_and_print_cr(" Min: %.1lf, Avg: %.1lf, Max: %.1lf, Diff: %.1lf, Sum: %.1lf]",
 190       min, avg, max, max - min, total);
 191   } else {
 192     buf.append_and_print_cr(" Min: %d, Avg: %d, Max: %d, Diff: %d, Sum: %d]",
 193       (int)min, (int)avg, (int)max, (int)max - (int)min, (int)total);
 194   }
 195 }
 196 
 197 void G1GCPhaseTimes::print_stats(int level, const char* str, double value) {
 198   LineBuffer(level).append_and_print_cr("[%s: %.1lf ms]", str, value);
 199 }
 200 
 201 void G1GCPhaseTimes::print_stats(int level, const char* str, double value, int workers) {
 202   LineBuffer(level).append_and_print_cr("[%s: %.1lf ms, GC Workers: %d]", str, value, workers);
 203 }
 204 
 205 void G1GCPhaseTimes::print_stats(int level, const char* str, int value) {
 206   LineBuffer(level).append_and_print_cr("[%s: %d]", str, value);
 207 }
 208 
 209 double G1GCPhaseTimes::avg_value(double* data) {
 210   if (G1CollectedHeap::use_parallel_gc_threads()) {
 211     double ret = 0.0;
 212     for (uint i = 0; i < _active_gc_threads; ++i) {
 213       ret += data[i];
 214     }
 215     return ret / (double) _active_gc_threads;
 216   } else {
 217     return data[0];
 218   }
 219 }
 220 
 221 double G1GCPhaseTimes::max_value(double* data) {
 222   if (G1CollectedHeap::use_parallel_gc_threads()) {
 223     double ret = data[0];
 224     for (uint i = 1; i < _active_gc_threads; ++i) {
 225       if (data[i] > ret) {
 226         ret = data[i];
 227       }
 228     }
 229     return ret;
 230   } else {
 231     return data[0];
 232   }
 233 }
 234 
 235 double G1GCPhaseTimes::sum_of_values(double* data) {
 236   if (G1CollectedHeap::use_parallel_gc_threads()) {
 237     double sum = 0.0;
 238     for (uint i = 0; i < _active_gc_threads; i++) {
 239       sum += data[i];
 240     }
 241     return sum;
 242   } else {
 243     return data[0];
 244   }
 245 }
 246 
 247 double G1GCPhaseTimes::max_sum(double* data1, double* data2) {
 248   double ret = data1[0] + data2[0];
 249 
 250   if (G1CollectedHeap::use_parallel_gc_threads()) {
 251     for (uint i = 1; i < _active_gc_threads; ++i) {
 252       double data = data1[i] + data2[i];
 253       if (data > ret) {
 254         ret = data;
 255       }
 256     }
 257   }
 258   return ret;
 259 }
 260 
 261 void G1GCPhaseTimes::collapse_par_times() {
 262     _ext_root_scan_time = avg_value(_par_last_ext_root_scan_times_ms);
 263     _satb_filtering_time = avg_value(_par_last_satb_filtering_times_ms);
 264     _update_rs_time = avg_value(_par_last_update_rs_times_ms);
 265     _update_rs_processed_buffers =
 266       sum_of_values(_par_last_update_rs_processed_buffers);
 267     _scan_rs_time = avg_value(_par_last_scan_rs_times_ms);
 268     _obj_copy_time = avg_value(_par_last_obj_copy_times_ms);
 269     _termination_time = avg_value(_par_last_termination_times_ms);
 270 }
 271 
 272 double G1GCPhaseTimes::accounted_time_ms() {
 273     // Subtract the root region scanning wait time. It's initialized to
 274     // zero at the start of the pause.
 275     double misc_time_ms = _root_region_scan_wait_time_ms;
 276 
 277     misc_time_ms += _cur_collection_par_time_ms;
 278 
 279     // Now subtract the time taken to fix up roots in generated code
 280     misc_time_ms += _cur_collection_code_root_fixup_time_ms;
 281 
 282     // Subtract the time taken to clean the card table from the
 283     // current value of "other time"
 284     misc_time_ms += _cur_clear_ct_time_ms;
 285 
 286     return misc_time_ms;
 287 }
 288 
 289 void G1GCPhaseTimes::print(double pause_time_ms) {
 290 
 291   if (PrintGCTimeStamps) {
 292     gclog_or_tty->stamp();
 293     gclog_or_tty->print(": ");
 294   }
 295 
 296   GCCauseString gc_cause_str = GCCauseString("GC pause", _gc_cause)
 297     .append(_is_young_gc ? " (young)" : " (mixed)")
 298     .append(_is_initial_mark_gc ? " (initial-mark)" : "");
 299   gclog_or_tty->print_cr("[%s, %3.7f secs]", (const char*)gc_cause_str, pause_time_ms / 1000.0);
 300 
 301   if (!G1Log::finer()) {
 302     return;
 303   }
 304 
 305   if (_root_region_scan_wait_time_ms > 0.0) {
 306     print_stats(1, "Root Region Scan Waiting", _root_region_scan_wait_time_ms);
 307   }
 308   if (G1CollectedHeap::use_parallel_gc_threads()) {
 309     print_stats(1, "Parallel Time", _cur_collection_par_time_ms, _active_gc_threads);
 310     print_par_stats(2, "GC Worker Start", _par_last_gc_worker_start_times_ms);
 311     print_par_stats(2, "Ext Root Scanning", _par_last_ext_root_scan_times_ms);
 312     if (_satb_filtering_time > 0.0) {
 313       print_par_stats(2, "SATB Filtering", _par_last_satb_filtering_times_ms);
 314     }
 315     print_par_stats(2, "Update RS", _par_last_update_rs_times_ms);
 316     if (G1Log::finest()) {
 317       print_par_stats(3, "Processed Buffers", _par_last_update_rs_processed_buffers,
 318         false /* showDecimals */);
 319     }
 320     print_par_stats(2, "Scan RS", _par_last_scan_rs_times_ms);
 321     print_par_stats(2, "Object Copy", _par_last_obj_copy_times_ms);
 322     print_par_stats(2, "Termination", _par_last_termination_times_ms);
 323     if (G1Log::finest()) {
 324       print_par_stats(3, "Termination Attempts", _par_last_termination_attempts,
 325         false /* showDecimals */);
 326     }
 327     print_par_stats(2, "GC Worker Other", _par_last_gc_worker_other_times_ms);
 328     print_par_stats(2, "GC Worker Total", _par_last_gc_worker_times_ms);
 329     print_par_stats(2, "GC Worker End", _par_last_gc_worker_end_times_ms);
 330   } else {
 331     print_stats(1, "Ext Root Scanning", _ext_root_scan_time);
 332     if (_satb_filtering_time > 0.0) {
 333       print_stats(1, "SATB Filtering", _satb_filtering_time);
 334     }
 335     print_stats(1, "Update RS", _update_rs_time);
 336     if (G1Log::finest()) {
 337       print_stats(2, "Processed Buffers", (int)_update_rs_processed_buffers);
 338     }
 339     print_stats(1, "Scan RS", _scan_rs_time);
 340     print_stats(1, "Object Copying", _obj_copy_time);
 341   }
 342   print_stats(1, "Code Root Fixup", _cur_collection_code_root_fixup_time_ms);
 343   print_stats(1, "Clear CT", _cur_clear_ct_time_ms);
 344   if (Verbose && G1Log::finest()) {
 345     print_stats(1, "Cur Clear CC", _cur_clear_cc_time_ms);
 346     print_stats(1, "Cum Clear CC", _cum_clear_cc_time_ms);
 347     print_stats(1, "Min Clear CC", _min_clear_cc_time_ms);
 348     print_stats(1, "Max Clear CC", _max_clear_cc_time_ms);
 349     if (_num_cc_clears > 0) {
 350       print_stats(1, "Avg Clear CC", _cum_clear_cc_time_ms / ((double)_num_cc_clears));
 351     }
 352   }
 353   double misc_time_ms = pause_time_ms - accounted_time_ms();
 354   print_stats(1, "Other", misc_time_ms);
 355   print_stats(2, "Choose CSet",
 356     (_recorded_young_cset_choice_time_ms +
 357     _recorded_non_young_cset_choice_time_ms));
 358   print_stats(2, "Ref Proc", _cur_ref_proc_time_ms);
 359   print_stats(2, "Ref Enq", _cur_ref_enq_time_ms);
 360   print_stats(2, "Free CSet",
 361     (_recorded_young_free_cset_time_ms +
 362     _recorded_non_young_free_cset_time_ms));
 363 }
 364 
 365 void G1GCPhaseTimes::record_cc_clear_time_ms(double ms) {
 366   if (!(Verbose && G1Log::finest())) {
 367     return;
 368   }
 369 
 370   if (_min_clear_cc_time_ms < 0.0 || ms <= _min_clear_cc_time_ms) {
 371     _min_clear_cc_time_ms = ms;
 372   }
 373   if (_max_clear_cc_time_ms < 0.0 || ms >= _max_clear_cc_time_ms) {
 374     _max_clear_cc_time_ms = ms;
 375   }
 376   _cur_clear_cc_time_ms = ms;
 377   _cum_clear_cc_time_ms += ms;
 378   _num_cc_clears++;
 379 }