libgomp/oacc-profiling.c

   1 /* OpenACC Profiling Interface
   2
   3    Copyright (C) 2019-2021 Free Software Foundation, Inc.
   4
   5    Contributed by Mentor, a Siemens Business.
   6
   7    This file is part of the GNU Offloading and Multi Processing Library
   8    (libgomp).
   9
  10    Libgomp is free software; you can redistribute it and/or modify it
  11    under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3, or (at your option)
  13    any later version.
  14
  15    Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
  16    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  17    FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  18    more details.
  19
  20    Under Section 7 of GPL version 3, you are granted additional
  21    permissions described in the GCC Runtime Library Exception, version
  22    3.1, as published by the Free Software Foundation.
  23
  24    You should have received a copy of the GNU General Public License and
  25    a copy of the GCC Runtime Library Exception along with this program;
  26    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  27    <http://www.gnu.org/licenses/>.  */
  28
  29 #define _GNU_SOURCE
  30 #include "libgomp.h"
  31 #include "oacc-int.h"
  32 #include "secure_getenv.h"
  33 #include "acc_prof.h"
  34 #include <assert.h>
  35 #ifdef HAVE_STRING_H
  36 # include <string.h>
  37 #endif
  38 #ifdef PLUGIN_SUPPORT
  39 # include <dlfcn.h>
  40 #endif
  41
  42 #define STATIC_ASSERT(expr) _Static_assert (expr, "!(" #expr ")")
  43
  44 /* Statically assert that the layout of the common fields in the
  45    'acc_event_info' variants matches.  */
  46 /* 'event_type' */
  47 STATIC_ASSERT (offsetof (acc_event_info, event_type)
  48                == offsetof (acc_event_info, data_event.event_type));
  49 STATIC_ASSERT (offsetof (acc_event_info, data_event.event_type)
  50                == offsetof (acc_event_info, launch_event.event_type));
  51 STATIC_ASSERT (offsetof (acc_event_info, data_event.event_type)
  52                == offsetof (acc_event_info, other_event.event_type));
  53 /* 'valid_bytes' */
  54 STATIC_ASSERT (offsetof (acc_event_info, data_event.valid_bytes)
  55                == offsetof (acc_event_info, launch_event.valid_bytes));
  56 STATIC_ASSERT (offsetof (acc_event_info, data_event.valid_bytes)
  57                == offsetof (acc_event_info, other_event.valid_bytes));
  58 /* 'parent_construct' */
  59 STATIC_ASSERT (offsetof (acc_event_info, data_event.parent_construct)
  60                == offsetof (acc_event_info, launch_event.parent_construct));
  61 STATIC_ASSERT (offsetof (acc_event_info, data_event.parent_construct)
  62                == offsetof (acc_event_info, other_event.parent_construct));
  63 /* 'implicit' */
  64 STATIC_ASSERT (offsetof (acc_event_info, data_event.implicit)
  65                == offsetof (acc_event_info, launch_event.implicit));
  66 STATIC_ASSERT (offsetof (acc_event_info, data_event.implicit)
  67                == offsetof (acc_event_info, other_event.implicit));
  68 /* 'tool_info' */
  69 STATIC_ASSERT (offsetof (acc_event_info, data_event.tool_info)
  70                == offsetof (acc_event_info, launch_event.tool_info));
  71 STATIC_ASSERT (offsetof (acc_event_info, data_event.tool_info)
  72                == offsetof (acc_event_info, other_event.tool_info));
  73
  74 struct goacc_prof_callback_entry
  75 {
  76   acc_prof_callback cb;
  77   int ref;
  78   bool enabled;
  79   struct goacc_prof_callback_entry *next;
  80 };
  81
  82 /* Use a separate flag to minimize run-time performance impact for the (very
  83    common) case that profiling is not enabled.
  84
  85    Once enabled, we're not going to disable this anymore, anywhere.  We
  86    probably could, by adding appropriate logic to 'acc_prof_register',
  87    'acc_prof_unregister'.  */
  88 bool goacc_prof_enabled = false;
  89
  90 /* Global state for registered callbacks.
  91    'goacc_prof_callbacks_enabled[acc_ev_none]' acts as a global toggle.  */
  92 static bool goacc_prof_callbacks_enabled[acc_ev_last];
  93 static struct goacc_prof_callback_entry *goacc_prof_callback_entries[acc_ev_last];
  94 /* Lock used to protect access to 'goacc_prof_callbacks_enabled', and
  95    'goacc_prof_callback_entries'.  */
  96 static gomp_mutex_t goacc_prof_lock;
  97
  98 void
  99 goacc_profiling_initialize (void)
 100 {
 101   gomp_mutex_init (&goacc_prof_lock);
 102
 103   /* Initially, all callbacks for all events are enabled.  */
 104   for (int i = 0; i < acc_ev_last; ++i)
 105     goacc_prof_callbacks_enabled[i] = true;
 106
 107
 108 #ifdef PLUGIN_SUPPORT
 109   char *acc_proflibs = secure_getenv ("ACC_PROFLIB");
 110   while (acc_proflibs != NULL && acc_proflibs[0] != '\0')
 111     {
 112       char *acc_proflibs_sep = strchr (acc_proflibs, ';');
 113       char *acc_proflib;
 114       if (acc_proflibs_sep == acc_proflibs)
 115         {
 116           /* Stray ';' separator: make sure we don't 'dlopen' the main
 117              program.  */
 118           acc_proflib = NULL;
 119         }
 120       else
 121         {
 122           if (acc_proflibs_sep != NULL)
 123             {
 124               /* Single out the first library.  */
 125               acc_proflib = gomp_malloc (acc_proflibs_sep - acc_proflibs + 1);
 126               memcpy (acc_proflib, acc_proflibs,
 127                       acc_proflibs_sep - acc_proflibs);
 128               acc_proflib[acc_proflibs_sep - acc_proflibs] = '\0';
 129             }
 130           else
 131             {
 132               /* No ';' separator, so only one library.  */
 133               acc_proflib = acc_proflibs;
 134             }
 135
 136           gomp_debug (0, "%s: dlopen (\"%s\")\n", __FUNCTION__, acc_proflib);
 137           void *dl_handle = dlopen (acc_proflib, RTLD_LAZY);
 138           if (dl_handle != NULL)
 139             {
 140               typeof (&acc_register_library) a_r_l
 141                 = dlsym (dl_handle, "acc_register_library");
 142               if (a_r_l == NULL)
 143                 goto dl_fail;
 144               gomp_debug (0, "  %s: calling %s:acc_register_library\n",
 145                           __FUNCTION__, acc_proflib);
 146               a_r_l (acc_prof_register, acc_prof_unregister,
 147                      acc_prof_lookup);
 148             }
 149           else
 150             {
 151             dl_fail:
 152               gomp_error ("while loading ACC_PROFLIB \"%s\": %s",
 153                           acc_proflib, dlerror ());
 154               if (dl_handle != NULL)
 155                 {
 156                   int err = dlclose (dl_handle);
 157                   dl_handle = NULL;
 158                   if (err != 0)
 159                     goto dl_fail;
 160                 }
 161             }
 162         }
 163
 164       if (acc_proflib != acc_proflibs)
 165         {
 166           free (acc_proflib);
 167
 168           acc_proflibs = acc_proflibs_sep + 1;
 169         }
 170       else
 171         acc_proflibs = NULL;
 172     }
 173 #endif /* PLUGIN_SUPPORT */
 174 }
 175
 176 void
 177 acc_prof_register (acc_event_t ev, acc_prof_callback cb, acc_register_t reg)
 178 {
 179   gomp_debug (0, "%s: ev=%d, cb=%p, reg=%d\n",
 180               __FUNCTION__, (int) ev, (void *) cb, (int) reg);
 181
 182
 183   /* For any events to be dispatched, the user first has to register a
 184      callback, which makes this here a good place for enabling the whole
 185      machinery.  */
 186   if (!GOACC_PROF_ENABLED)
 187     __atomic_store_n (&goacc_prof_enabled, true, MEMMODEL_RELEASE);
 188
 189
 190   enum
 191   {
 192     EVENT_KIND_BOGUS,
 193     EVENT_KIND_NORMAL,
 194     /* As end events invoke callbacks in the reverse order, we register these
 195        in the reverse order here.  */
 196     EVENT_KIND_END,
 197   } event_kind = EVENT_KIND_BOGUS;
 198   switch (ev)
 199     {
 200     case acc_ev_none:
 201     case acc_ev_device_init_start:
 202     case acc_ev_device_shutdown_start:
 203     case acc_ev_runtime_shutdown:
 204     case acc_ev_create:
 205     case acc_ev_delete:
 206     case acc_ev_alloc:
 207     case acc_ev_free:
 208     case acc_ev_enter_data_start:
 209     case acc_ev_exit_data_start:
 210     case acc_ev_update_start:
 211     case acc_ev_compute_construct_start:
 212     case acc_ev_enqueue_launch_start:
 213     case acc_ev_enqueue_upload_start:
 214     case acc_ev_enqueue_download_start:
 215     case acc_ev_wait_start:
 216       event_kind = EVENT_KIND_NORMAL;
 217       break;
 218     case acc_ev_device_init_end:
 219     case acc_ev_device_shutdown_end:
 220     case acc_ev_enter_data_end:
 221     case acc_ev_exit_data_end:
 222     case acc_ev_update_end:
 223     case acc_ev_compute_construct_end:
 224     case acc_ev_enqueue_launch_end:
 225     case acc_ev_enqueue_upload_end:
 226     case acc_ev_enqueue_download_end:
 227     case acc_ev_wait_end:
 228       event_kind = EVENT_KIND_END;
 229       break;
 230     case acc_ev_last:
 231       break;
 232     }
 233   if (event_kind == EVENT_KIND_BOGUS)
 234     {
 235       /* Silently ignore.  */
 236       gomp_debug (0, "  ignoring request for bogus 'acc_event_t'\n");
 237       return;
 238     }
 239
 240   bool bogus = true;
 241   switch (reg)
 242     {
 243     case acc_reg:
 244     case acc_toggle:
 245     case acc_toggle_per_thread:
 246       bogus = false;
 247       break;
 248     }
 249   if (bogus)
 250     {
 251       /* Silently ignore.  */
 252       gomp_debug (0, "  ignoring request with bogus 'acc_register_t'\n");
 253       return;
 254     }
 255
 256   /* Special cases.  */
 257   if (reg == acc_toggle)
 258     {
 259       if (cb == NULL)
 260         {
 261           gomp_debug (0, "  globally enabling callbacks\n");
 262           gomp_mutex_lock (&goacc_prof_lock);
 263           /* For 'acc_ev_none', this acts as a global toggle.  */
 264           goacc_prof_callbacks_enabled[ev] = true;
 265           gomp_mutex_unlock (&goacc_prof_lock);
 266           return;
 267         }
 268       else if (ev == acc_ev_none && cb != NULL)
 269         {
 270           gomp_debug (0, "  ignoring request\n");
 271           return;
 272         }
 273     }
 274   else if (reg == acc_toggle_per_thread)
 275     {
 276       if (ev == acc_ev_none && cb == NULL)
 277         {
 278           gomp_debug (0, "  thread: enabling callbacks\n");
 279           goacc_lazy_initialize ();
 280           struct goacc_thread *thr = goacc_thread ();
 281           thr->prof_callbacks_enabled = true;
 282           return;
 283         }
 284       /* Silently ignore.  */
 285       gomp_debug (0, "  ignoring bogus request\n");
 286       return;
 287     }
 288
 289   gomp_mutex_lock (&goacc_prof_lock);
 290
 291   struct goacc_prof_callback_entry *it, *it_p;
 292   it = goacc_prof_callback_entries[ev];
 293   it_p = NULL;
 294   while (it)
 295     {
 296       if (it->cb == cb)
 297         break;
 298       it_p = it;
 299       it = it->next;
 300     }
 301
 302   switch (reg)
 303     {
 304     case acc_reg:
 305       /* If we already have this callback registered, just increment its
 306          reference count.  */
 307       if (it != NULL)
 308         {
 309           it->ref++;
 310           gomp_debug (0, "  already registered;"
 311                       " incrementing reference count to: %d\n", it->ref);
 312         }
 313       else
 314         {
 315           struct goacc_prof_callback_entry *e
 316             = gomp_malloc (sizeof (struct goacc_prof_callback_entry));
 317           e->cb = cb;
 318           e->ref = 1;
 319           e->enabled = true;
 320           bool prepend = (event_kind == EVENT_KIND_END);
 321           /* If we don't have any callback registered yet, also use the
 322              'prepend' code path.  */
 323           if (it_p == NULL)
 324             prepend = true;
 325           if (prepend)
 326             {
 327               gomp_debug (0, "  prepending\n");
 328               e->next = goacc_prof_callback_entries[ev];
 329               goacc_prof_callback_entries[ev] = e;
 330             }
 331           else
 332             {
 333               gomp_debug (0, "  appending\n");
 334               e->next = NULL;
 335               it_p->next = e;
 336             }
 337         }
 338       break;
 339
 340     case acc_toggle:
 341       if (it == NULL)
 342         {
 343           gomp_debug (0, "  ignoring request: is not registered\n");
 344           break;
 345         }
 346       else
 347         {
 348           gomp_debug (0, "  enabling\n");
 349           it->enabled = true;
 350         }
 351       break;
 352
 353     case acc_toggle_per_thread:
 354       __builtin_unreachable ();
 355     }
 356
 357   gomp_mutex_unlock (&goacc_prof_lock);
 358 }
 359
 360 void
 361 acc_prof_unregister (acc_event_t ev, acc_prof_callback cb, acc_register_t reg)
 362 {
 363   gomp_debug (0, "%s: ev=%d, cb=%p, reg=%d\n",
 364               __FUNCTION__, (int) ev, (void *) cb, (int) reg);
 365
 366   /* If profiling is not enabled, there cannot be anything to unregister.  */
 367   if (!GOACC_PROF_ENABLED)
 368     return;
 369
 370   if (ev < acc_ev_none
 371       || ev >= acc_ev_last)
 372     {
 373       /* Silently ignore.  */
 374       gomp_debug (0, "  ignoring request for bogus 'acc_event_t'\n");
 375       return;
 376     }
 377
 378   bool bogus = true;
 379   switch (reg)
 380     {
 381     case acc_reg:
 382     case acc_toggle:
 383     case acc_toggle_per_thread:
 384       bogus = false;
 385       break;
 386     }
 387   if (bogus)
 388     {
 389       /* Silently ignore.  */
 390       gomp_debug (0, "  ignoring request with bogus 'acc_register_t'\n");
 391       return;
 392     }
 393
 394   /* Special cases.  */
 395   if (reg == acc_toggle)
 396     {
 397       if (cb == NULL)
 398         {
 399           gomp_debug (0, "  globally disabling callbacks\n");
 400           gomp_mutex_lock (&goacc_prof_lock);
 401           /* For 'acc_ev_none', this acts as a global toggle.  */
 402           goacc_prof_callbacks_enabled[ev] = false;
 403           gomp_mutex_unlock (&goacc_prof_lock);
 404           return;
 405         }
 406       else if (ev == acc_ev_none && cb != NULL)
 407         {
 408           gomp_debug (0, "  ignoring request\n");
 409           return;
 410         }
 411     }
 412   else if (reg == acc_toggle_per_thread)
 413     {
 414       if (ev == acc_ev_none && cb == NULL)
 415         {
 416           gomp_debug (0, "  thread: disabling callbacks\n");
 417           goacc_lazy_initialize ();
 418           struct goacc_thread *thr = goacc_thread ();
 419           thr->prof_callbacks_enabled = false;
 420           return;
 421         }
 422       /* Silently ignore.  */
 423       gomp_debug (0, "  ignoring bogus request\n");
 424       return;
 425     }
 426
 427   gomp_mutex_lock (&goacc_prof_lock);
 428
 429   struct goacc_prof_callback_entry *it, *it_p;
 430   it = goacc_prof_callback_entries[ev];
 431   it_p = NULL;
 432   while (it)
 433     {
 434       if (it->cb == cb)
 435         break;
 436       it_p = it;
 437       it = it->next;
 438     }
 439
 440   switch (reg)
 441     {
 442     case acc_reg:
 443       if (it == NULL)
 444         {
 445           /* Silently ignore.  */
 446           gomp_debug (0, "  ignoring bogus request: is not registered\n");
 447           break;
 448         }
 449       it->ref--;
 450       gomp_debug (0, "  decrementing reference count to: %d\n", it->ref);
 451       if (it->ref == 0)
 452         {
 453           if (it_p == NULL)
 454             goacc_prof_callback_entries[ev] = it->next;
 455           else
 456             it_p->next = it->next;
 457           free (it);
 458         }
 459       break;
 460
 461     case acc_toggle:
 462       if (it == NULL)
 463         {
 464           gomp_debug (0, "  ignoring request: is not registered\n");
 465           break;
 466         }
 467       else
 468         {
 469           gomp_debug (0, "  disabling\n");
 470           it->enabled = false;
 471         }
 472       break;
 473
 474     case acc_toggle_per_thread:
 475       __builtin_unreachable ();
 476     }
 477
 478   gomp_mutex_unlock (&goacc_prof_lock);
 479 }
 480
 481 acc_query_fn
 482 acc_prof_lookup (const char *name)
 483 {
 484   gomp_debug (0, "%s (%s)\n",
 485               __FUNCTION__, name ?: "NULL");
 486
 487   return NULL;
 488 }
 489
 490 void
 491 acc_register_library (acc_prof_reg reg, acc_prof_reg unreg,
 492                       acc_prof_lookup_func lookup)
 493 {
 494   gomp_fatal ("TODO");
 495 }
 496
 497 /* Prepare to dispatch events?  */
 498
 499 bool
 500 _goacc_profiling_dispatch_p (bool check_not_nested_p)
 501 {
 502   gomp_debug (0, "%s\n", __FUNCTION__);
 503
 504   bool ret;
 505
 506   struct goacc_thread *thr = goacc_thread ();
 507   if (__builtin_expect (thr == NULL, false))
 508     {
 509       /* If we don't have any per-thread state yet, that means that per-thread
 510          callback dispatch has not been explicitly disabled (which only a call
 511          to 'acc_prof_unregister' with 'acc_toggle_per_thread' would do, and
 512          that would have allocated per-thread state via
 513          'goacc_lazy_initialize'); initially, all callbacks for all events are
 514          enabled.  */
 515       gomp_debug (0, "  %s: don't have any per-thread state yet\n", __FUNCTION__);
 516     }
 517   else
 518     {
 519       if (check_not_nested_p)
 520         {
 521           /* No nesting.  */
 522           assert (thr->prof_info == NULL);
 523           assert (thr->api_info == NULL);
 524         }
 525
 526       if (__builtin_expect (!thr->prof_callbacks_enabled, true))
 527         {
 528           gomp_debug (0, "  %s: disabled for this thread\n", __FUNCTION__);
 529           ret = false;
 530           goto out;
 531         }
 532     }
 533
 534   gomp_mutex_lock (&goacc_prof_lock);
 535
 536   /* 'goacc_prof_callbacks_enabled[acc_ev_none]' acts as a global toggle.  */
 537   if (__builtin_expect (!goacc_prof_callbacks_enabled[acc_ev_none], true))
 538     {
 539       gomp_debug (0, "  %s: disabled globally\n", __FUNCTION__);
 540       ret = false;
 541       goto out_unlock;
 542     }
 543   else
 544     ret = true;
 545
 546  out_unlock:
 547   gomp_mutex_unlock (&goacc_prof_lock);
 548
 549  out:
 550   return ret;
 551 }
 552
 553 /* Set up to dispatch events?  */
 554
 555 bool
 556 _goacc_profiling_setup_p (struct goacc_thread *thr,
 557                           acc_prof_info *prof_info, acc_api_info *api_info)
 558 {
 559   gomp_debug (0, "%s (%p)\n", __FUNCTION__, thr);
 560
 561   /* If we don't have any per-thread state yet, we can't register 'prof_info'
 562      and 'api_info'.  */
 563   if (__builtin_expect (thr == NULL, false))
 564     {
 565       gomp_debug (0, "Can't dispatch OpenACC Profiling Interface events for"
 566                   " the current call, construct, or directive\n");
 567       return false;
 568     }
 569
 570   if (thr->prof_info != NULL)
 571     {
 572       /* Profiling has already been set up for an outer construct.  In this
 573          case, we continue to use the existing information, and thus return
 574          'false' here.
 575
 576          This can happen, for example, for an 'enter data' directive, which
 577          sets up profiling, then calls into 'acc_copyin', which should not
 578          again set up profiling, should not overwrite the existing
 579          information.  */
 580       return false;
 581     }
 582
 583   thr->prof_info = prof_info;
 584   thr->api_info = api_info;
 585
 586   /* Fill in some defaults.  */
 587
 588   prof_info->event_type = -1; /* Must be set later.  */
 589   prof_info->valid_bytes = _ACC_PROF_INFO_VALID_BYTES;
 590   prof_info->version = _ACC_PROF_INFO_VERSION;
 591   if (thr->dev)
 592     {
 593       prof_info->device_type = acc_device_type (thr->dev->type);
 594       prof_info->device_number = thr->dev->target_id;
 595     }
 596   else
 597     {
 598       prof_info->device_type = -1;
 599       prof_info->device_number = -1;
 600     }
 601   prof_info->thread_id = -1;
 602   prof_info->async = acc_async_sync;
 603   prof_info->async_queue = prof_info->async;
 604   prof_info->src_file = NULL;
 605   prof_info->func_name = NULL;
 606   prof_info->line_no = -1;
 607   prof_info->end_line_no = -1;
 608   prof_info->func_line_no = -1;
 609   prof_info->func_end_line_no = -1;
 610
 611   api_info->device_api = acc_device_api_none;
 612   api_info->valid_bytes = _ACC_API_INFO_VALID_BYTES;
 613   api_info->device_type = prof_info->device_type;
 614   api_info->vendor = -1;
 615   api_info->device_handle = NULL;
 616   api_info->context_handle = NULL;
 617   api_info->async_handle = NULL;
 618
 619   return true;
 620 }
 621
 622 /* Dispatch events.
 623
 624    This must only be called if 'GOACC_PROFILING_DISPATCH_P' or
 625    'GOACC_PROFILING_SETUP_P' returned a true result.  */
 626
 627 void
 628 goacc_profiling_dispatch (acc_prof_info *prof_info, acc_event_info *event_info,
 629                           acc_api_info *apt_info)
 630 {
 631   acc_event_t event_type = event_info->event_type;
 632   gomp_debug (0, "%s: event_type=%d\n", __FUNCTION__, (int) event_type);
 633   assert (event_type > acc_ev_none
 634           && event_type < acc_ev_last);
 635
 636   gomp_mutex_lock (&goacc_prof_lock);
 637
 638   if (!goacc_prof_callbacks_enabled[event_type])
 639     {
 640       gomp_debug (0, "  disabled for this event type\n");
 641
 642       goto out_unlock;
 643     }
 644
 645   for (struct goacc_prof_callback_entry *e
 646          = goacc_prof_callback_entries[event_type];
 647        e != NULL;
 648        e = e->next)
 649     {
 650       if (!e->enabled)
 651         {
 652           gomp_debug (0, "  disabled for callback %p\n", e->cb);
 653           continue;
 654         }
 655
 656       gomp_debug (0, "  calling callback %p\n", e->cb);
 657       e->cb (prof_info, event_info, apt_info);
 658     }
 659
 660  out_unlock:
 661   gomp_mutex_unlock (&goacc_prof_lock);
 662 }