src/vnet/session/segment_manager.c

   1 /*
   2  * Copyright (c) 2017 Cisco and/or its affiliates.
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15
  16 #include <vnet/session/segment_manager.h>
  17 #include <vnet/session/session.h>
  18 #include <vnet/session/application.h>
  19
  20 /**
  21  * Counter used to build segment names
  22  */
  23 u32 segment_name_counter = 0;
  24
  25 /**
  26  * Pool of segment managers
  27  */
  28 segment_manager_t *segment_managers = 0;
  29
  30 /**
  31  * Process private segment index
  32  */
  33 u32 *private_segment_indices;
  34
  35 /**
  36  * Default fifo and segment size. TODO config.
  37  */
  38 u32 default_fifo_size = 1 << 16;
  39 u32 default_segment_size = 1 << 20;
  40
  41 void
  42 segment_manager_get_segment_info (u32 index, u8 ** name, u32 * size)
  43 {
  44   svm_fifo_segment_private_t *s;
  45   s = svm_fifo_segment_get_segment (index);
  46   *name = s->h->segment_name;
  47   *size = s->ssvm.ssvm_size;
  48 }
  49
  50 always_inline int
  51 session_manager_add_segment_i (segment_manager_t * sm, u32 segment_size,
  52                                u8 * segment_name)
  53 {
  54   svm_fifo_segment_create_args_t _ca, *ca = &_ca;
  55   int rv;
  56
  57   memset (ca, 0, sizeof (*ca));
  58
  59   if (!sm->properties->use_private_segment)
  60     {
  61       ca->segment_name = (char *) segment_name;
  62       ca->segment_size = segment_size;
  63       ca->rx_fifo_size = sm->properties->rx_fifo_size;
  64       ca->tx_fifo_size = sm->properties->tx_fifo_size;
  65       ca->preallocated_fifo_pairs = sm->properties->preallocated_fifo_pairs;
  66
  67       rv = svm_fifo_segment_create (ca);
  68       if (rv)
  69         {
  70           clib_warning ("svm_fifo_segment_create ('%s', %d) failed",
  71                         ca->segment_name, ca->segment_size);
  72           return VNET_API_ERROR_SVM_SEGMENT_CREATE_FAIL;
  73         }
  74     }
  75   else
  76     {
  77       u32 rx_fifo_size, tx_fifo_size, rx_rounded_data_size,
  78         tx_rounded_data_size;
  79       u32 approx_segment_count;
  80       u64 approx_total_size;
  81
  82       ca->segment_name = "process-private-segment";
  83       ca->segment_size = ~0;
  84       ca->rx_fifo_size = sm->properties->rx_fifo_size;
  85       ca->tx_fifo_size = sm->properties->tx_fifo_size;
  86       ca->preallocated_fifo_pairs = sm->properties->preallocated_fifo_pairs;
  87       ca->private_segment_count = sm->properties->private_segment_count;
  88       ca->private_segment_size = sm->properties->private_segment_size;
  89
  90       /* Default to a small private segment */
  91       if (ca->private_segment_size == 0)
  92         ca->private_segment_size = 128 << 20;
  93
  94       /* Calculate space requirements */
  95       rx_rounded_data_size = (1 << (max_log2 (ca->rx_fifo_size)));
  96       tx_rounded_data_size = (1 << (max_log2 (ca->tx_fifo_size)));
  97
  98       rx_fifo_size = sizeof (svm_fifo_t) + rx_rounded_data_size;
  99       tx_fifo_size = sizeof (svm_fifo_t) + tx_rounded_data_size;
 100
 101       approx_total_size = (u64) ca->preallocated_fifo_pairs
 102         * (rx_fifo_size + tx_fifo_size);
 103       approx_segment_count =
 104         (approx_total_size +
 105          (ca->private_segment_size - 1)) / (u64) ca->private_segment_size;
 106
 107       /* The user asked us to figure it out... */
 108       if (ca->private_segment_count == 0)
 109         {
 110           ca->private_segment_count = approx_segment_count;
 111         }
 112       /* Follow directions, but issue a warning */
 113       else if (approx_segment_count != ca->private_segment_count)
 114         {
 115           clib_warning
 116             ("Honoring segment count %u, but calculated count was %u",
 117              ca->private_segment_count, approx_segment_count);
 118         }
 119
 120       if (svm_fifo_segment_create_process_private (ca))
 121         clib_warning ("Failed to create process private segment");
 122
 123       ASSERT (vec_len (ca->new_segment_indices));
 124     }
 125   vec_append (sm->segment_indices, ca->new_segment_indices);
 126   vec_free (ca->new_segment_indices);
 127   return 0;
 128 }
 129
 130 int
 131 session_manager_add_segment (segment_manager_t * sm)
 132 {
 133   u8 *segment_name;
 134   svm_fifo_segment_create_args_t _ca, *ca = &_ca;
 135   u32 add_segment_size;
 136   int rv;
 137
 138   memset (ca, 0, sizeof (*ca));
 139   segment_name = format (0, "%d-%d%c", getpid (), segment_name_counter++, 0);
 140   add_segment_size = sm->properties->add_segment_size ?
 141     sm->properties->add_segment_size : default_segment_size;
 142
 143   rv = session_manager_add_segment_i (sm, add_segment_size, segment_name);
 144   vec_free (segment_name);
 145   return rv;
 146 }
 147
 148 int
 149 session_manager_add_first_segment (segment_manager_t * sm, u32 segment_size)
 150 {
 151   u8 *segment_name;
 152   int rv;
 153
 154   segment_name = format (0, "%d-%d%c", getpid (), segment_name_counter++, 0);
 155   rv = session_manager_add_segment_i (sm, segment_size, segment_name);
 156   vec_free (segment_name);
 157   return rv;
 158 }
 159
 160 segment_manager_t *
 161 segment_manager_new ()
 162 {
 163   segment_manager_t *sm;
 164   pool_get (segment_managers, sm);
 165   memset (sm, 0, sizeof (*sm));
 166   return sm;
 167 }
 168
 169 /**
 170  * Initializes segment manager based on options provided.
 171  * Returns error if svm segment allocation fails.
 172  */
 173 int
 174 segment_manager_init (segment_manager_t * sm,
 175                       segment_manager_properties_t * properties,
 176                       u32 first_seg_size)
 177 {
 178   int rv;
 179
 180   /* app allocates these */
 181   sm->properties = properties;
 182
 183   first_seg_size = first_seg_size > 0 ? first_seg_size : default_segment_size;
 184
 185   rv = session_manager_add_first_segment (sm, first_seg_size);
 186   if (rv)
 187     {
 188       clib_warning ("Failed to allocate segment");
 189       return rv;
 190     }
 191
 192   clib_spinlock_init (&sm->lockp);
 193   return 0;
 194 }
 195
 196 u8
 197 segment_manager_has_fifos (segment_manager_t * sm)
 198 {
 199   svm_fifo_segment_private_t *segment;
 200   int i;
 201
 202   for (i = 0; i < vec_len (sm->segment_indices); i++)
 203     {
 204       segment = svm_fifo_segment_get_segment (sm->segment_indices[i]);
 205       if (CLIB_DEBUG && i && !svm_fifo_segment_has_fifos (segment)
 206           && !(segment->h->flags & FIFO_SEGMENT_F_IS_PREALLOCATED))
 207         clib_warning ("segment %d has no fifos!", sm->segment_indices[i]);
 208       if (svm_fifo_segment_has_fifos (segment))
 209         return 1;
 210     }
 211   return 0;
 212 }
 213
 214 static u8
 215 segment_manager_app_detached (segment_manager_t * sm)
 216 {
 217   return (sm->app_index == SEGMENT_MANAGER_INVALID_APP_INDEX);
 218 }
 219
 220 static void
 221 segment_manager_del_segment (segment_manager_t * sm, u32 segment_index)
 222 {
 223   svm_fifo_segment_private_t *fifo_segment;
 224   u32 svm_segment_index;
 225   clib_spinlock_lock (&sm->lockp);
 226   svm_segment_index = sm->segment_indices[segment_index];
 227   fifo_segment = svm_fifo_segment_get_segment (svm_segment_index);
 228   if (!fifo_segment
 229       || ((fifo_segment->h->flags & FIFO_SEGMENT_F_IS_PREALLOCATED)
 230           && !segment_manager_app_detached (sm)))
 231     {
 232       clib_spinlock_unlock (&sm->lockp);
 233       return;
 234     }
 235   svm_fifo_segment_delete (fifo_segment);
 236   vec_del1 (sm->segment_indices, segment_index);
 237   clib_spinlock_unlock (&sm->lockp);
 238 }
 239
 240 /**
 241  * Initiate disconnects for all sessions 'owned' by a segment manager
 242  */
 243 void
 244 segment_manager_del_sessions (segment_manager_t * sm)
 245 {
 246   int j;
 247   svm_fifo_segment_private_t *fifo_segment;
 248   svm_fifo_t *fifo;
 249
 250   ASSERT (vec_len (sm->segment_indices));
 251
 252   /* Across all fifo segments used by the server */
 253   for (j = 0; j < vec_len (sm->segment_indices); j++)
 254     {
 255       fifo_segment = svm_fifo_segment_get_segment (sm->segment_indices[j]);
 256       fifo = svm_fifo_segment_get_fifo_list (fifo_segment);
 257
 258       /*
 259        * Remove any residual sessions from the session lookup table
 260        * Don't bother deleting the individual fifos, we're going to
 261        * throw away the fifo segment in a minute.
 262        */
 263       while (fifo)
 264         {
 265           u32 session_index, thread_index;
 266           stream_session_t *session;
 267
 268           session_index = fifo->master_session_index;
 269           thread_index = fifo->master_thread_index;
 270           session = session_get (session_index, thread_index);
 271
 272           /* Instead of directly removing the session call disconnect */
 273           if (session->session_state != SESSION_STATE_CLOSED)
 274             {
 275               session->session_state = SESSION_STATE_CLOSED;
 276               session_send_session_evt_to_thread (session_handle
 277                                                   (session),
 278                                                   FIFO_EVENT_DISCONNECT,
 279                                                   thread_index);
 280             }
 281           fifo = fifo->next;
 282         }
 283
 284       /* Instead of removing the segment, test when cleaning up disconnected
 285        * sessions if the segment can be removed.
 286        */
 287     }
 288 }
 289
 290 /**
 291  * Removes segment manager.
 292  *
 293  * Since the fifos allocated in the segment keep backpointers to the sessions
 294  * prior to removing the segment, we call session disconnect. This
 295  * subsequently propagates into transport.
 296  */
 297 void
 298 segment_manager_del (segment_manager_t * sm)
 299 {
 300   int i;
 301
 302   ASSERT (!segment_manager_has_fifos (sm)
 303           && segment_manager_app_detached (sm));
 304
 305   /* If we have empty preallocated segments that haven't been removed, remove
 306    * them now. Apart from that, the first segment in the first segment manager
 307    * is not removed when all fifos are removed. It can only be removed when
 308    * the manager is explicitly deleted/detached by the app. */
 309   for (i = vec_len (sm->segment_indices) - 1; i >= 0; i--)
 310     {
 311       if (CLIB_DEBUG)
 312         {
 313           svm_fifo_segment_private_t *segment;
 314           segment = svm_fifo_segment_get_segment (sm->segment_indices[i]);
 315           ASSERT (!svm_fifo_segment_has_fifos (segment));
 316         }
 317       segment_manager_del_segment (sm, i);
 318     }
 319   clib_spinlock_free (&sm->lockp);
 320   if (CLIB_DEBUG)
 321     memset (sm, 0xfe, sizeof (*sm));
 322   pool_put (segment_managers, sm);
 323 }
 324
 325 void
 326 segment_manager_init_del (segment_manager_t * sm)
 327 {
 328   if (segment_manager_has_fifos (sm))
 329     segment_manager_del_sessions (sm);
 330   else
 331     {
 332       ASSERT (!sm->first_is_protected || segment_manager_app_detached (sm));
 333       segment_manager_del (sm);
 334     }
 335 }
 336
 337 int
 338 segment_manager_alloc_session_fifos (segment_manager_t * sm,
 339                                      svm_fifo_t ** server_rx_fifo,
 340                                      svm_fifo_t ** server_tx_fifo,
 341                                      u32 * fifo_segment_index)
 342 {
 343   svm_fifo_segment_private_t *fifo_segment;
 344   u32 fifo_size, sm_index;
 345   u8 added_a_segment = 0;
 346   int i;
 347
 348   ASSERT (vec_len (sm->segment_indices));
 349
 350   /* Make sure we don't have multiple threads trying to allocate segments
 351    * at the same time. */
 352   clib_spinlock_lock (&sm->lockp);
 353
 354   /* Allocate svm fifos */
 355 again:
 356   for (i = 0; i < vec_len (sm->segment_indices); i++)
 357     {
 358       *fifo_segment_index = sm->segment_indices[i];
 359       fifo_segment = svm_fifo_segment_get_segment (*fifo_segment_index);
 360
 361       fifo_size = sm->properties->rx_fifo_size;
 362       fifo_size = (fifo_size == 0) ? default_fifo_size : fifo_size;
 363       *server_rx_fifo =
 364         svm_fifo_segment_alloc_fifo (fifo_segment, fifo_size,
 365                                      FIFO_SEGMENT_RX_FREELIST);
 366
 367       fifo_size = sm->properties->tx_fifo_size;
 368       fifo_size = (fifo_size == 0) ? default_fifo_size : fifo_size;
 369       *server_tx_fifo =
 370         svm_fifo_segment_alloc_fifo (fifo_segment, fifo_size,
 371                                      FIFO_SEGMENT_TX_FREELIST);
 372
 373       if (*server_rx_fifo == 0)
 374         {
 375           /* This would be very odd, but handle it... */
 376           if (*server_tx_fifo != 0)
 377             {
 378               svm_fifo_segment_free_fifo (fifo_segment, *server_tx_fifo,
 379                                           FIFO_SEGMENT_TX_FREELIST);
 380               *server_tx_fifo = 0;
 381             }
 382           continue;
 383         }
 384       if (*server_tx_fifo == 0)
 385         {
 386           if (*server_rx_fifo != 0)
 387             {
 388               svm_fifo_segment_free_fifo (fifo_segment, *server_rx_fifo,
 389                                           FIFO_SEGMENT_RX_FREELIST);
 390               *server_rx_fifo = 0;
 391             }
 392           continue;
 393         }
 394       break;
 395     }
 396
 397   /* See if we're supposed to create another segment */
 398   if (*server_rx_fifo == 0)
 399     {
 400       if (sm->properties->add_segment && !sm->properties->use_private_segment)
 401         {
 402           if (added_a_segment)
 403             {
 404               clib_warning ("added a segment, still can't allocate a fifo");
 405               clib_spinlock_unlock (&sm->lockp);
 406               return SESSION_ERROR_NEW_SEG_NO_SPACE;
 407             }
 408
 409           if (session_manager_add_segment (sm))
 410             {
 411               clib_spinlock_unlock (&sm->lockp);
 412               return VNET_API_ERROR_URI_FIFO_CREATE_FAILED;
 413             }
 414
 415           added_a_segment = 1;
 416           goto again;
 417         }
 418       else
 419         {
 420           clib_warning ("No space to allocate fifos!");
 421           clib_spinlock_unlock (&sm->lockp);
 422           return SESSION_ERROR_NO_SPACE;
 423         }
 424     }
 425
 426   /* Backpointers to segment manager */
 427   sm_index = segment_manager_index (sm);
 428   (*server_tx_fifo)->segment_manager = sm_index;
 429   (*server_rx_fifo)->segment_manager = sm_index;
 430
 431   clib_spinlock_unlock (&sm->lockp);
 432
 433   if (added_a_segment)
 434     return application_add_segment_notify (sm->app_index,
 435                                            *fifo_segment_index);
 436
 437   return 0;
 438 }
 439
 440 void
 441 segment_manager_dealloc_fifos (u32 svm_segment_index, svm_fifo_t * rx_fifo,
 442                                svm_fifo_t * tx_fifo)
 443 {
 444   segment_manager_t *sm;
 445   svm_fifo_segment_private_t *fifo_segment;
 446   u32 i, segment_index = ~0;
 447   u8 is_first;
 448
 449   sm = segment_manager_get_if_valid (rx_fifo->segment_manager);
 450
 451   /* It's possible to have no segment manager if the session was removed
 452    * as result of a detach. */
 453   if (!sm)
 454     return;
 455
 456   fifo_segment = svm_fifo_segment_get_segment (svm_segment_index);
 457   svm_fifo_segment_free_fifo (fifo_segment, rx_fifo,
 458                               FIFO_SEGMENT_RX_FREELIST);
 459   svm_fifo_segment_free_fifo (fifo_segment, tx_fifo,
 460                               FIFO_SEGMENT_TX_FREELIST);
 461
 462   /*
 463    * Try to remove svm segment if it has no fifos. This can be done only if
 464    * the segment is not the first in the segment manager or if it is first
 465    * and it is not protected. Moreover, if the segment is first and the app
 466    * has detached from the segment manager, remove the segment manager.
 467    */
 468   if (!svm_fifo_segment_has_fifos (fifo_segment))
 469     {
 470       is_first = sm->segment_indices[0] == svm_segment_index;
 471
 472       /* Remove segment if it holds no fifos or first but not protected */
 473       if (!is_first || !sm->first_is_protected)
 474         {
 475           /* Find the segment manager segment index */
 476           for (i = 0; i < vec_len (sm->segment_indices); i++)
 477             if (sm->segment_indices[i] == svm_segment_index)
 478               {
 479                 segment_index = i;
 480                 break;
 481               }
 482           ASSERT (segment_index != (u32) ~ 0);
 483           segment_manager_del_segment (sm, segment_index);
 484         }
 485
 486       /* Remove segment manager if no sessions and detached from app */
 487       if (segment_manager_app_detached (sm)
 488           && !segment_manager_has_fifos (sm))
 489         segment_manager_del (sm);
 490     }
 491 }
 492
 493 /**
 494  * Allocates shm queue in the first segment
 495  */
 496 unix_shared_memory_queue_t *
 497 segment_manager_alloc_queue (segment_manager_t * sm, u32 queue_size)
 498 {
 499   ssvm_shared_header_t *sh;
 500   svm_fifo_segment_private_t *segment;
 501   unix_shared_memory_queue_t *q;
 502   void *oldheap;
 503
 504   ASSERT (sm->segment_indices != 0);
 505
 506   segment = svm_fifo_segment_get_segment (sm->segment_indices[0]);
 507   sh = segment->ssvm.sh;
 508
 509   oldheap = ssvm_push_heap (sh);
 510   q = unix_shared_memory_queue_init (queue_size,
 511                                      sizeof (session_fifo_event_t),
 512                                      0 /* consumer pid */ ,
 513                                      0 /* signal when queue non-empty */ );
 514   ssvm_pop_heap (oldheap);
 515   return q;
 516 }
 517
 518 /**
 519  * Frees shm queue allocated in the first segment
 520  */
 521 void
 522 segment_manager_dealloc_queue (segment_manager_t * sm,
 523                                unix_shared_memory_queue_t * q)
 524 {
 525   ssvm_shared_header_t *sh;
 526   svm_fifo_segment_private_t *segment;
 527   void *oldheap;
 528
 529   ASSERT (sm->segment_indices != 0);
 530
 531   segment = svm_fifo_segment_get_segment (sm->segment_indices[0]);
 532   sh = segment->ssvm.sh;
 533
 534   oldheap = ssvm_push_heap (sh);
 535   unix_shared_memory_queue_free (q);
 536   ssvm_pop_heap (oldheap);
 537 }
 538
 539 static clib_error_t *
 540 segment_manager_show_fn (vlib_main_t * vm, unformat_input_t * input,
 541                          vlib_cli_command_t * cmd)
 542 {
 543   svm_fifo_segment_private_t *segments, *seg;
 544   segment_manager_t *sm;
 545   u8 show_segments = 0, verbose = 0, *name;
 546   uword address;
 547   u64 size;
 548   u32 active_fifos;
 549   u32 free_fifos;
 550
 551   mheap_t *heap_header;
 552
 553   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
 554     {
 555       if (unformat (input, "segments"))
 556         show_segments = 1;
 557       else if (unformat (input, "verbose"))
 558         verbose = 1;
 559       else
 560         return clib_error_return (0, "unknown input `%U'",
 561                                   format_unformat_error, input);
 562     }
 563   vlib_cli_output (vm, "%d segment managers allocated",
 564                    pool_elts (segment_managers));
 565   if (verbose && pool_elts (segment_managers))
 566     {
 567       vlib_cli_output (vm, "%-10s%=15s%=12s", "Index", "App Index",
 568                        "Segments");
 569
 570       /* *INDENT-OFF* */
 571       pool_foreach (sm, segment_managers, ({
 572         vlib_cli_output (vm, "%-10d%=15d%=12d", segment_manager_index(sm),
 573                            sm->app_index, vec_len (sm->segment_indices));
 574       }));
 575       /* *INDENT-ON* */
 576
 577     }
 578   if (show_segments)
 579     {
 580       segments = svm_fifo_segment_segments_pool ();
 581       vlib_cli_output (vm, "%d svm fifo segments allocated",
 582                        pool_elts (segments));
 583       vlib_cli_output (vm, "%-20s%=12s%=16s%=16s%=16s", "Name",
 584                        "HeapSize (M)", "ActiveFifos", "FreeFifos", "Address");
 585
 586       /* *INDENT-OFF* */
 587       pool_foreach (seg, segments, ({
 588         if (seg->h->flags & FIFO_SEGMENT_F_IS_PRIVATE)
 589           {
 590             address = pointer_to_uword (seg->ssvm.sh->heap);
 591             if (seg->h->flags & FIFO_SEGMENT_F_IS_MAIN_HEAP)
 592               name = format (0, "main heap");
 593             else
 594               name = format (0, "private heap");
 595             heap_header = mheap_header (seg->ssvm.sh->heap);
 596             size = heap_header->max_size;
 597           }
 598         else
 599           {
 600             address =  seg->ssvm.sh->ssvm_va;
 601             size = seg->ssvm.ssvm_size;
 602             name = seg->ssvm.sh->name;
 603           }
 604         active_fifos = svm_fifo_segment_num_fifos (seg);
 605         free_fifos = svm_fifo_segment_num_free_fifos (seg, ~0 /* size */);
 606         vlib_cli_output (vm, "%-20v%=16llu%=16u%=16u%16llx",
 607                          name, size >> 20ULL, active_fifos, free_fifos,
 608                          address);
 609         if (verbose)
 610           vlib_cli_output (vm, "%U",
 611                            format_svm_fifo_segment, seg, verbose);
 612         if (seg->h->flags & FIFO_SEGMENT_F_IS_PRIVATE)
 613           vec_free (name);
 614       }));
 615       /* *INDENT-ON* */
 616
 617     }
 618   return 0;
 619 }
 620
 621                           /* *INDENT-OFF* */
 622 VLIB_CLI_COMMAND (segment_manager_show_command, static) =
 623 {
 624   .path = "show segment-manager",
 625   .short_help = "show segment-manager [segments][verbose]",
 626   .function = segment_manager_show_fn,
 627 };
 628 /* *INDENT-ON* */
 629
 630 /*
 631  * fd.io coding-style-patch-verification: ON
 632  *
 633  * Local Variables:
 634  * eval: (c-set-style "gnu")
 635  * End:
 636  */