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 void
 221 segment_manager_app_detach (segment_manager_t * sm)
 222 {
 223   sm->app_index = SEGMENT_MANAGER_INVALID_APP_INDEX;
 224 }
 225
 226 static void
 227 segment_manager_del_segment (segment_manager_t * sm, u32 segment_index)
 228 {
 229   svm_fifo_segment_private_t *fifo_segment;
 230   u32 svm_segment_index;
 231   clib_spinlock_lock (&sm->lockp);
 232   svm_segment_index = sm->segment_indices[segment_index];
 233   fifo_segment = svm_fifo_segment_get_segment (svm_segment_index);
 234   if (!fifo_segment
 235       || ((fifo_segment->h->flags & FIFO_SEGMENT_F_IS_PREALLOCATED)
 236           && !segment_manager_app_detached (sm)))
 237     {
 238       clib_spinlock_unlock (&sm->lockp);
 239       return;
 240     }
 241   svm_fifo_segment_delete (fifo_segment);
 242   vec_del1 (sm->segment_indices, segment_index);
 243   clib_spinlock_unlock (&sm->lockp);
 244 }
 245
 246 /**
 247  * Initiate disconnects for all sessions 'owned' by a segment manager
 248  */
 249 void
 250 segment_manager_del_sessions (segment_manager_t * sm)
 251 {
 252   int j;
 253   svm_fifo_segment_private_t *fifo_segment;
 254   svm_fifo_t *fifo;
 255
 256   ASSERT (vec_len (sm->segment_indices));
 257
 258   /* Across all fifo segments used by the server */
 259   for (j = 0; j < vec_len (sm->segment_indices); j++)
 260     {
 261       fifo_segment = svm_fifo_segment_get_segment (sm->segment_indices[j]);
 262       fifo = svm_fifo_segment_get_fifo_list (fifo_segment);
 263
 264       /*
 265        * Remove any residual sessions from the session lookup table
 266        * Don't bother deleting the individual fifos, we're going to
 267        * throw away the fifo segment in a minute.
 268        */
 269       while (fifo)
 270         {
 271           u32 session_index, thread_index;
 272           stream_session_t *session;
 273
 274           session_index = fifo->master_session_index;
 275           thread_index = fifo->master_thread_index;
 276           session = session_get (session_index, thread_index);
 277
 278           /* Instead of directly removing the session call disconnect */
 279           if (session->session_state != SESSION_STATE_CLOSED)
 280             {
 281               session->session_state = SESSION_STATE_CLOSED;
 282               session_send_session_evt_to_thread (session_handle
 283                                                   (session),
 284                                                   FIFO_EVENT_DISCONNECT,
 285                                                   thread_index);
 286             }
 287           fifo = fifo->next;
 288         }
 289
 290       /* Instead of removing the segment, test when cleaning up disconnected
 291        * sessions if the segment can be removed.
 292        */
 293     }
 294 }
 295
 296 /**
 297  * Removes segment manager.
 298  *
 299  * Since the fifos allocated in the segment keep backpointers to the sessions
 300  * prior to removing the segment, we call session disconnect. This
 301  * subsequently propagates into transport.
 302  */
 303 void
 304 segment_manager_del (segment_manager_t * sm)
 305 {
 306   int i;
 307
 308   ASSERT (!segment_manager_has_fifos (sm)
 309           && segment_manager_app_detached (sm));
 310
 311   /* If we have empty preallocated segments that haven't been removed, remove
 312    * them now. Apart from that, the first segment in the first segment manager
 313    * is not removed when all fifos are removed. It can only be removed when
 314    * the manager is explicitly deleted/detached by the app. */
 315   for (i = vec_len (sm->segment_indices) - 1; i >= 0; i--)
 316     {
 317       if (CLIB_DEBUG)
 318         {
 319           svm_fifo_segment_private_t *segment;
 320           segment = svm_fifo_segment_get_segment (sm->segment_indices[i]);
 321           ASSERT (!svm_fifo_segment_has_fifos (segment));
 322         }
 323       segment_manager_del_segment (sm, i);
 324     }
 325   clib_spinlock_free (&sm->lockp);
 326   if (CLIB_DEBUG)
 327     memset (sm, 0xfe, sizeof (*sm));
 328   pool_put (segment_managers, sm);
 329 }
 330
 331 void
 332 segment_manager_init_del (segment_manager_t * sm)
 333 {
 334   segment_manager_app_detach (sm);
 335   if (segment_manager_has_fifos (sm))
 336     segment_manager_del_sessions (sm);
 337   else
 338     {
 339       ASSERT (!sm->first_is_protected || segment_manager_app_detached (sm));
 340       segment_manager_del (sm);
 341     }
 342 }
 343
 344 int
 345 segment_manager_alloc_session_fifos (segment_manager_t * sm,
 346                                      svm_fifo_t ** server_rx_fifo,
 347                                      svm_fifo_t ** server_tx_fifo,
 348                                      u32 * fifo_segment_index)
 349 {
 350   svm_fifo_segment_private_t *fifo_segment;
 351   u32 fifo_size, sm_index;
 352   u8 added_a_segment = 0;
 353   int i;
 354
 355   ASSERT (vec_len (sm->segment_indices));
 356
 357   /* Make sure we don't have multiple threads trying to allocate segments
 358    * at the same time. */
 359   clib_spinlock_lock (&sm->lockp);
 360
 361   /* Allocate svm fifos */
 362 again:
 363   for (i = 0; i < vec_len (sm->segment_indices); i++)
 364     {
 365       *fifo_segment_index = sm->segment_indices[i];
 366       fifo_segment = svm_fifo_segment_get_segment (*fifo_segment_index);
 367
 368       fifo_size = sm->properties->rx_fifo_size;
 369       fifo_size = (fifo_size == 0) ? default_fifo_size : fifo_size;
 370       *server_rx_fifo =
 371         svm_fifo_segment_alloc_fifo (fifo_segment, fifo_size,
 372                                      FIFO_SEGMENT_RX_FREELIST);
 373
 374       fifo_size = sm->properties->tx_fifo_size;
 375       fifo_size = (fifo_size == 0) ? default_fifo_size : fifo_size;
 376       *server_tx_fifo =
 377         svm_fifo_segment_alloc_fifo (fifo_segment, fifo_size,
 378                                      FIFO_SEGMENT_TX_FREELIST);
 379
 380       if (*server_rx_fifo == 0)
 381         {
 382           /* This would be very odd, but handle it... */
 383           if (*server_tx_fifo != 0)
 384             {
 385               svm_fifo_segment_free_fifo (fifo_segment, *server_tx_fifo,
 386                                           FIFO_SEGMENT_TX_FREELIST);
 387               *server_tx_fifo = 0;
 388             }
 389           continue;
 390         }
 391       if (*server_tx_fifo == 0)
 392         {
 393           if (*server_rx_fifo != 0)
 394             {
 395               svm_fifo_segment_free_fifo (fifo_segment, *server_rx_fifo,
 396                                           FIFO_SEGMENT_RX_FREELIST);
 397               *server_rx_fifo = 0;
 398             }
 399           continue;
 400         }
 401       break;
 402     }
 403
 404   /* See if we're supposed to create another segment */
 405   if (*server_rx_fifo == 0)
 406     {
 407       if (sm->properties->add_segment && !sm->properties->use_private_segment)
 408         {
 409           if (added_a_segment)
 410             {
 411               clib_warning ("added a segment, still can't allocate a fifo");
 412               clib_spinlock_unlock (&sm->lockp);
 413               return SESSION_ERROR_NEW_SEG_NO_SPACE;
 414             }
 415
 416           if (session_manager_add_segment (sm))
 417             {
 418               clib_spinlock_unlock (&sm->lockp);
 419               return VNET_API_ERROR_URI_FIFO_CREATE_FAILED;
 420             }
 421
 422           added_a_segment = 1;
 423           goto again;
 424         }
 425       else
 426         {
 427           clib_warning ("No space to allocate fifos!");
 428           clib_spinlock_unlock (&sm->lockp);
 429           return SESSION_ERROR_NO_SPACE;
 430         }
 431     }
 432
 433   /* Backpointers to segment manager */
 434   sm_index = segment_manager_index (sm);
 435   (*server_tx_fifo)->segment_manager = sm_index;
 436   (*server_rx_fifo)->segment_manager = sm_index;
 437
 438   clib_spinlock_unlock (&sm->lockp);
 439
 440   if (added_a_segment)
 441     return application_add_segment_notify (sm->app_index,
 442                                            *fifo_segment_index);
 443
 444   return 0;
 445 }
 446
 447 void
 448 segment_manager_dealloc_fifos (u32 svm_segment_index, svm_fifo_t * rx_fifo,
 449                                svm_fifo_t * tx_fifo)
 450 {
 451   segment_manager_t *sm;
 452   svm_fifo_segment_private_t *fifo_segment;
 453   u32 i, segment_index = ~0;
 454   u8 is_first;
 455
 456   sm = segment_manager_get_if_valid (rx_fifo->segment_manager);
 457
 458   /* It's possible to have no segment manager if the session was removed
 459    * as result of a detach. */
 460   if (!sm)
 461     return;
 462
 463   fifo_segment = svm_fifo_segment_get_segment (svm_segment_index);
 464   svm_fifo_segment_free_fifo (fifo_segment, rx_fifo,
 465                               FIFO_SEGMENT_RX_FREELIST);
 466   svm_fifo_segment_free_fifo (fifo_segment, tx_fifo,
 467                               FIFO_SEGMENT_TX_FREELIST);
 468
 469   /*
 470    * Try to remove svm segment if it has no fifos. This can be done only if
 471    * the segment is not the first in the segment manager or if it is first
 472    * and it is not protected. Moreover, if the segment is first and the app
 473    * has detached from the segment manager, remove the segment manager.
 474    */
 475   if (!svm_fifo_segment_has_fifos (fifo_segment))
 476     {
 477       is_first = sm->segment_indices[0] == svm_segment_index;
 478
 479       /* Remove segment if it holds no fifos or first but not protected */
 480       if (!is_first || !sm->first_is_protected)
 481         {
 482           /* Find the segment manager segment index */
 483           for (i = 0; i < vec_len (sm->segment_indices); i++)
 484             if (sm->segment_indices[i] == svm_segment_index)
 485               {
 486                 segment_index = i;
 487                 break;
 488               }
 489           ASSERT (segment_index != (u32) ~ 0);
 490           segment_manager_del_segment (sm, segment_index);
 491         }
 492
 493       /* Remove segment manager if no sessions and detached from app */
 494       if (segment_manager_app_detached (sm)
 495           && !segment_manager_has_fifos (sm))
 496         segment_manager_del (sm);
 497     }
 498 }
 499
 500 /**
 501  * Allocates shm queue in the first segment
 502  */
 503 unix_shared_memory_queue_t *
 504 segment_manager_alloc_queue (segment_manager_t * sm, u32 queue_size)
 505 {
 506   ssvm_shared_header_t *sh;
 507   svm_fifo_segment_private_t *segment;
 508   unix_shared_memory_queue_t *q;
 509   void *oldheap;
 510
 511   ASSERT (sm->segment_indices != 0);
 512
 513   segment = svm_fifo_segment_get_segment (sm->segment_indices[0]);
 514   sh = segment->ssvm.sh;
 515
 516   oldheap = ssvm_push_heap (sh);
 517   q = unix_shared_memory_queue_init (queue_size,
 518                                      sizeof (session_fifo_event_t),
 519                                      0 /* consumer pid */ ,
 520                                      0 /* signal when queue non-empty */ );
 521   ssvm_pop_heap (oldheap);
 522   return q;
 523 }
 524
 525 /**
 526  * Frees shm queue allocated in the first segment
 527  */
 528 void
 529 segment_manager_dealloc_queue (segment_manager_t * sm,
 530                                unix_shared_memory_queue_t * q)
 531 {
 532   ssvm_shared_header_t *sh;
 533   svm_fifo_segment_private_t *segment;
 534   void *oldheap;
 535
 536   ASSERT (sm->segment_indices != 0);
 537
 538   segment = svm_fifo_segment_get_segment (sm->segment_indices[0]);
 539   sh = segment->ssvm.sh;
 540
 541   oldheap = ssvm_push_heap (sh);
 542   unix_shared_memory_queue_free (q);
 543   ssvm_pop_heap (oldheap);
 544 }
 545
 546 static clib_error_t *
 547 segment_manager_show_fn (vlib_main_t * vm, unformat_input_t * input,
 548                          vlib_cli_command_t * cmd)
 549 {
 550   svm_fifo_segment_private_t *segments, *seg;
 551   segment_manager_t *sm;
 552   u8 show_segments = 0, verbose = 0, *name;
 553   uword address;
 554   u64 size;
 555   u32 active_fifos;
 556   u32 free_fifos;
 557
 558   mheap_t *heap_header;
 559
 560   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
 561     {
 562       if (unformat (input, "segments"))
 563         show_segments = 1;
 564       else if (unformat (input, "verbose"))
 565         verbose = 1;
 566       else
 567         return clib_error_return (0, "unknown input `%U'",
 568                                   format_unformat_error, input);
 569     }
 570   vlib_cli_output (vm, "%d segment managers allocated",
 571                    pool_elts (segment_managers));
 572   if (verbose && pool_elts (segment_managers))
 573     {
 574       vlib_cli_output (vm, "%-10s%=15s%=12s", "Index", "App Index",
 575                        "Segments");
 576
 577       /* *INDENT-OFF* */
 578       pool_foreach (sm, segment_managers, ({
 579         vlib_cli_output (vm, "%-10d%=15d%=12d", segment_manager_index(sm),
 580                            sm->app_index, vec_len (sm->segment_indices));
 581       }));
 582       /* *INDENT-ON* */
 583
 584     }
 585   if (show_segments)
 586     {
 587       segments = svm_fifo_segment_segments_pool ();
 588       vlib_cli_output (vm, "%d svm fifo segments allocated",
 589                        pool_elts (segments));
 590       vlib_cli_output (vm, "%-20s%=12s%=16s%=16s%=16s", "Name",
 591                        "HeapSize (M)", "ActiveFifos", "FreeFifos", "Address");
 592
 593       /* *INDENT-OFF* */
 594       pool_foreach (seg, segments, ({
 595         if (seg->h->flags & FIFO_SEGMENT_F_IS_PRIVATE)
 596           {
 597             address = pointer_to_uword (seg->ssvm.sh->heap);
 598             if (seg->h->flags & FIFO_SEGMENT_F_IS_MAIN_HEAP)
 599               name = format (0, "main heap");
 600             else
 601               name = format (0, "private heap");
 602             heap_header = mheap_header (seg->ssvm.sh->heap);
 603             size = heap_header->max_size;
 604           }
 605         else
 606           {
 607             address =  seg->ssvm.sh->ssvm_va;
 608             size = seg->ssvm.ssvm_size;
 609             name = seg->ssvm.sh->name;
 610           }
 611         active_fifos = svm_fifo_segment_num_fifos (seg);
 612         free_fifos = svm_fifo_segment_num_free_fifos (seg, ~0 /* size */);
 613         vlib_cli_output (vm, "%-20v%=16llu%=16u%=16u%16llx",
 614                          name, size >> 20ULL, active_fifos, free_fifos,
 615                          address);
 616         if (verbose)
 617           vlib_cli_output (vm, "%U",
 618                            format_svm_fifo_segment, seg, verbose);
 619         if (seg->h->flags & FIFO_SEGMENT_F_IS_PRIVATE)
 620           vec_free (name);
 621       }));
 622       /* *INDENT-ON* */
 623
 624     }
 625   return 0;
 626 }
 627
 628                           /* *INDENT-OFF* */
 629 VLIB_CLI_COMMAND (segment_manager_show_command, static) =
 630 {
 631   .path = "show segment-manager",
 632   .short_help = "show segment-manager [segments][verbose]",
 633   .function = segment_manager_show_fn,
 634 };
 635 /* *INDENT-ON* */
 636
 637 /*
 638  * fd.io coding-style-patch-verification: ON
 639  *
 640  * Local Variables:
 641  * eval: (c-set-style "gnu")
 642  * End:
 643  */