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   /* Weird, but handle it */
 201   if (vec_len (sm->segment_indices) == 0)
 202     return 0;
 203   if (vec_len (sm->segment_indices) == 1)
 204     {
 205       segment = svm_fifo_segment_get_segment (sm->segment_indices[0]);
 206       if (svm_fifo_segment_num_fifos (segment) == 0)
 207         return 0;
 208     }
 209   if (CLIB_DEBUG)
 210     {
 211       svm_fifo_segment_private_t *segment;
 212       int i;
 213       for (i = 1; i < vec_len (sm->segment_indices); i++)
 214         {
 215           segment = svm_fifo_segment_get_segment (sm->segment_indices[i]);
 216           if (!svm_fifo_segment_has_fifos (segment))
 217             clib_warning ("segment has no fifos!");
 218         }
 219     }
 220   return 1;
 221 }
 222
 223 static void
 224 segment_manager_del_segment (segment_manager_t * sm, u32 segment_index)
 225 {
 226   svm_fifo_segment_private_t *fifo_segment;
 227   u32 svm_segment_index;
 228   clib_spinlock_lock (&sm->lockp);
 229   svm_segment_index = sm->segment_indices[segment_index];
 230   fifo_segment = svm_fifo_segment_get_segment (svm_segment_index);
 231   svm_fifo_segment_delete (fifo_segment);
 232   vec_del1 (sm->segment_indices, segment_index);
 233   clib_spinlock_unlock (&sm->lockp);
 234 }
 235
 236 /**
 237  * Initiate disconnects for all sessions 'owned' by a segment manager
 238  */
 239 void
 240 segment_manager_del_sessions (segment_manager_t * sm)
 241 {
 242   int j;
 243   svm_fifo_segment_private_t *fifo_segment;
 244   svm_fifo_t *fifo;
 245
 246   ASSERT (vec_len (sm->segment_indices));
 247
 248   /* Across all fifo segments used by the server */
 249   for (j = 0; j < vec_len (sm->segment_indices); j++)
 250     {
 251       fifo_segment = svm_fifo_segment_get_segment (sm->segment_indices[j]);
 252       fifo = svm_fifo_segment_get_fifo_list (fifo_segment);
 253
 254       /*
 255        * Remove any residual sessions from the session lookup table
 256        * Don't bother deleting the individual fifos, we're going to
 257        * throw away the fifo segment in a minute.
 258        */
 259       while (fifo)
 260         {
 261           u32 session_index, thread_index;
 262           stream_session_t *session;
 263
 264           session_index = fifo->master_session_index;
 265           thread_index = fifo->master_thread_index;
 266           session = stream_session_get (session_index, thread_index);
 267
 268           /* Instead of directly removing the session call disconnect */
 269           if (session->session_state != SESSION_STATE_CLOSED)
 270             {
 271               session->session_state = SESSION_STATE_CLOSED;
 272               session_send_session_evt_to_thread (stream_session_handle
 273                                                   (session),
 274                                                   FIFO_EVENT_DISCONNECT,
 275                                                   thread_index);
 276             }
 277           fifo = fifo->next;
 278         }
 279
 280       /* Instead of removing the segment, test when cleaning up disconnected
 281        * sessions if the segment can be removed.
 282        */
 283     }
 284 }
 285
 286 /**
 287  * Removes segment manager.
 288  *
 289  * Since the fifos allocated in the segment keep backpointers to the sessions
 290  * prior to removing the segment, we call session disconnect. This
 291  * subsequently propages into transport.
 292  */
 293 void
 294 segment_manager_del (segment_manager_t * sm)
 295 {
 296
 297   ASSERT (vec_len (sm->segment_indices) <= 1);
 298   if (vec_len (sm->segment_indices))
 299     {
 300       /* The first segment in the first segment manager is not removed when
 301        * all fifos are removed. It can only be removed when the manager is
 302        * explicitly deleted/detached by the app. */
 303       if (CLIB_DEBUG)
 304         {
 305           svm_fifo_segment_private_t *fifo_segment;
 306           fifo_segment =
 307             svm_fifo_segment_get_segment (sm->segment_indices[0]);
 308           ASSERT (!svm_fifo_segment_has_fifos (fifo_segment));
 309         }
 310       segment_manager_del_segment (sm, 0);
 311     }
 312   clib_spinlock_free (&sm->lockp);
 313   if (CLIB_DEBUG)
 314     memset (sm, 0xfe, sizeof (*sm));
 315   pool_put (segment_managers, sm);
 316 }
 317
 318 void
 319 segment_manager_init_del (segment_manager_t * sm)
 320 {
 321   if (segment_manager_has_fifos (sm))
 322     segment_manager_del_sessions (sm);
 323   else
 324     {
 325       ASSERT (!sm->first_is_protected
 326               || sm->app_index == SEGMENT_MANAGER_INVALID_APP_INDEX);
 327       segment_manager_del (sm);
 328     }
 329 }
 330
 331 int
 332 segment_manager_alloc_session_fifos (segment_manager_t * sm,
 333                                      svm_fifo_t ** server_rx_fifo,
 334                                      svm_fifo_t ** server_tx_fifo,
 335                                      u32 * fifo_segment_index)
 336 {
 337   svm_fifo_segment_private_t *fifo_segment;
 338   u32 fifo_size, sm_index;
 339   u8 added_a_segment = 0;
 340   int i;
 341
 342   ASSERT (vec_len (sm->segment_indices));
 343
 344   /* Make sure we don't have multiple threads trying to allocate segments
 345    * at the same time. */
 346   clib_spinlock_lock (&sm->lockp);
 347
 348   /* Allocate svm fifos */
 349 again:
 350   for (i = 0; i < vec_len (sm->segment_indices); i++)
 351     {
 352       *fifo_segment_index = sm->segment_indices[i];
 353       fifo_segment = svm_fifo_segment_get_segment (*fifo_segment_index);
 354
 355       fifo_size = sm->properties->rx_fifo_size;
 356       fifo_size = (fifo_size == 0) ? default_fifo_size : fifo_size;
 357       *server_rx_fifo =
 358         svm_fifo_segment_alloc_fifo (fifo_segment, fifo_size,
 359                                      FIFO_SEGMENT_RX_FREELIST);
 360
 361       fifo_size = sm->properties->tx_fifo_size;
 362       fifo_size = (fifo_size == 0) ? default_fifo_size : fifo_size;
 363       *server_tx_fifo =
 364         svm_fifo_segment_alloc_fifo (fifo_segment, fifo_size,
 365                                      FIFO_SEGMENT_TX_FREELIST);
 366
 367       if (*server_rx_fifo == 0)
 368         {
 369           /* This would be very odd, but handle it... */
 370           if (*server_tx_fifo != 0)
 371             {
 372               svm_fifo_segment_free_fifo (fifo_segment, *server_tx_fifo,
 373                                           FIFO_SEGMENT_TX_FREELIST);
 374               *server_tx_fifo = 0;
 375             }
 376           continue;
 377         }
 378       if (*server_tx_fifo == 0)
 379         {
 380           if (*server_rx_fifo != 0)
 381             {
 382               svm_fifo_segment_free_fifo (fifo_segment, *server_rx_fifo,
 383                                           FIFO_SEGMENT_RX_FREELIST);
 384               *server_rx_fifo = 0;
 385             }
 386           continue;
 387         }
 388       break;
 389     }
 390
 391   /* See if we're supposed to create another segment */
 392   if (*server_rx_fifo == 0)
 393     {
 394       if (sm->properties->add_segment && !sm->properties->use_private_segment)
 395         {
 396           if (added_a_segment)
 397             {
 398               clib_warning ("added a segment, still can't allocate a fifo");
 399               clib_spinlock_unlock (&sm->lockp);
 400               return SESSION_ERROR_NEW_SEG_NO_SPACE;
 401             }
 402
 403           if (session_manager_add_segment (sm))
 404             {
 405               clib_spinlock_unlock (&sm->lockp);
 406               return VNET_API_ERROR_URI_FIFO_CREATE_FAILED;
 407             }
 408
 409           added_a_segment = 1;
 410           goto again;
 411         }
 412       else
 413         {
 414           clib_warning ("No space to allocate fifos!");
 415           clib_spinlock_unlock (&sm->lockp);
 416           return SESSION_ERROR_NO_SPACE;
 417         }
 418     }
 419
 420   /* Backpointers to segment manager */
 421   sm_index = segment_manager_index (sm);
 422   (*server_tx_fifo)->segment_manager = sm_index;
 423   (*server_rx_fifo)->segment_manager = sm_index;
 424
 425   clib_spinlock_unlock (&sm->lockp);
 426
 427   if (added_a_segment)
 428     return application_add_segment_notify (sm->app_index,
 429                                            *fifo_segment_index);
 430
 431   return 0;
 432 }
 433
 434 void
 435 segment_manager_dealloc_fifos (u32 svm_segment_index, svm_fifo_t * rx_fifo,
 436                                svm_fifo_t * tx_fifo)
 437 {
 438   segment_manager_t *sm;
 439   svm_fifo_segment_private_t *fifo_segment;
 440   u32 i, segment_index = ~0;
 441   u8 is_first;
 442
 443   sm = segment_manager_get_if_valid (rx_fifo->segment_manager);
 444
 445   /* It's possible to have no segment manager if the session was removed
 446    * as result of a detach. */
 447   if (!sm)
 448     return;
 449
 450   fifo_segment = svm_fifo_segment_get_segment (svm_segment_index);
 451   svm_fifo_segment_free_fifo (fifo_segment, rx_fifo,
 452                               FIFO_SEGMENT_RX_FREELIST);
 453   svm_fifo_segment_free_fifo (fifo_segment, tx_fifo,
 454                               FIFO_SEGMENT_TX_FREELIST);
 455
 456   /*
 457    * Try to remove svm segment if it has no fifos. This can be done only if
 458    * the segment is not the first in the segment manager or if it is first
 459    * and it is not protected. Moreover, if the segment is first and the app
 460    * has detached from the segment manager, remove the segment manager.
 461    */
 462   if (!svm_fifo_segment_has_fifos (fifo_segment))
 463     {
 464       is_first = sm->segment_indices[0] == svm_segment_index;
 465
 466       /* Remove segment if it holds no fifos or first but not protected */
 467       if (!is_first || !sm->first_is_protected)
 468         {
 469           /* Find the segment manager segment index */
 470           for (i = 0; i < vec_len (sm->segment_indices); i++)
 471             if (sm->segment_indices[i] == svm_segment_index)
 472               {
 473                 segment_index = i;
 474                 break;
 475               }
 476           ASSERT (segment_index != (u32) ~ 0);
 477           segment_manager_del_segment (sm, segment_index);
 478         }
 479
 480       /* Remove segment manager if no sessions and detached from app */
 481       if (sm->app_index == SEGMENT_MANAGER_INVALID_APP_INDEX && is_first)
 482         segment_manager_del (sm);
 483     }
 484 }
 485
 486 /**
 487  * Allocates shm queue in the first segment
 488  */
 489 unix_shared_memory_queue_t *
 490 segment_manager_alloc_queue (segment_manager_t * sm, u32 queue_size)
 491 {
 492   ssvm_shared_header_t *sh;
 493   svm_fifo_segment_private_t *segment;
 494   unix_shared_memory_queue_t *q;
 495   void *oldheap;
 496
 497   ASSERT (sm->segment_indices != 0);
 498
 499   segment = svm_fifo_segment_get_segment (sm->segment_indices[0]);
 500   sh = segment->ssvm.sh;
 501
 502   oldheap = ssvm_push_heap (sh);
 503   q = unix_shared_memory_queue_init (queue_size,
 504                                      sizeof (session_fifo_event_t),
 505                                      0 /* consumer pid */ ,
 506                                      0 /* signal when queue non-empty */ );
 507   ssvm_pop_heap (oldheap);
 508   return q;
 509 }
 510
 511 /**
 512  * Frees shm queue allocated in the first segment
 513  */
 514 void
 515 segment_manager_dealloc_queue (segment_manager_t * sm,
 516                                unix_shared_memory_queue_t * q)
 517 {
 518   ssvm_shared_header_t *sh;
 519   svm_fifo_segment_private_t *segment;
 520   void *oldheap;
 521
 522   ASSERT (sm->segment_indices != 0);
 523
 524   segment = svm_fifo_segment_get_segment (sm->segment_indices[0]);
 525   sh = segment->ssvm.sh;
 526
 527   oldheap = ssvm_push_heap (sh);
 528   unix_shared_memory_queue_free (q);
 529   ssvm_pop_heap (oldheap);
 530 }
 531
 532 static clib_error_t *
 533 segment_manager_show_fn (vlib_main_t * vm, unformat_input_t * input,
 534                          vlib_cli_command_t * cmd)
 535 {
 536   svm_fifo_segment_private_t *segments, *seg;
 537   segment_manager_t *sm;
 538   u8 show_segments = 0, verbose = 0, *name;
 539   uword address;
 540   u64 size;
 541   u32 active_fifos;
 542   u32 free_fifos;
 543
 544   mheap_t *heap_header;
 545
 546   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
 547     {
 548       if (unformat (input, "segments"))
 549         show_segments = 1;
 550       else if (unformat (input, "verbose"))
 551         verbose = 1;
 552       else
 553         return clib_error_return (0, "unknown input `%U'",
 554                                   format_unformat_error, input);
 555     }
 556   vlib_cli_output (vm, "%d segment managers allocated",
 557                    pool_elts (segment_managers));
 558   if (verbose && pool_elts (segment_managers))
 559     {
 560       vlib_cli_output (vm, "%-10s%=15s%=12s", "Index", "App Index",
 561                        "Segments");
 562
 563       /* *INDENT-OFF* */
 564       pool_foreach (sm, segment_managers, ({
 565         vlib_cli_output (vm, "%-10d%=15d%=12d", segment_manager_index(sm),
 566                            sm->app_index, vec_len (sm->segment_indices));
 567       }));
 568       /* *INDENT-ON* */
 569
 570     }
 571   if (show_segments)
 572     {
 573       segments = svm_fifo_segment_segments_pool ();
 574       vlib_cli_output (vm, "%d svm fifo segments allocated",
 575                        pool_elts (segments));
 576       vlib_cli_output (vm, "%-20s%=12s%=16s%=16s%=16s", "Name",
 577                        "HeapSize (M)", "ActiveFifos", "FreeFifos", "Address");
 578
 579       /* *INDENT-OFF* */
 580       pool_foreach (seg, segments, ({
 581         if (seg->h->flags & FIFO_SEGMENT_F_IS_PRIVATE)
 582           {
 583             address = pointer_to_uword (seg->ssvm.sh->heap);
 584             if (seg->h->flags & FIFO_SEGMENT_F_IS_MAIN_HEAP)
 585               name = format (0, "main heap");
 586             else
 587               name = format (0, "private heap");
 588             heap_header = mheap_header (seg->ssvm.sh->heap);
 589             size = heap_header->max_size;
 590           }
 591         else
 592           {
 593             address =  seg->ssvm.sh->ssvm_va;
 594             size = seg->ssvm.ssvm_size;
 595             name = seg->ssvm.sh->name;
 596           }
 597         active_fifos = svm_fifo_segment_num_fifos (seg);
 598         free_fifos = svm_fifo_segment_num_free_fifos (seg, ~0 /* size */);
 599         vlib_cli_output (vm, "%-20v%=16llu%=16u%=16u%16llx",
 600                          name, size >> 20ULL, active_fifos, free_fifos,
 601                          address);
 602         if (verbose)
 603           vlib_cli_output (vm, "%U",
 604                            format_svm_fifo_segment, seg, verbose);
 605         if (seg->h->flags & FIFO_SEGMENT_F_IS_PRIVATE)
 606           vec_free (name);
 607       }));
 608       /* *INDENT-ON* */
 609
 610     }
 611   return 0;
 612 }
 613
 614                           /* *INDENT-OFF* */
 615 VLIB_CLI_COMMAND (segment_manager_show_command, static) =
 616 {
 617   .path = "show segment-manager",
 618   .short_help = "show segment-manager [segments][verbose]",
 619   .function = segment_manager_show_fn,
 620 };
 621 /* *INDENT-ON* */
 622
 623 /*
 624  * fd.io coding-style-patch-verification: ON
 625  *
 626  * Local Variables:
 627  * eval: (c-set-style "gnu")
 628  * End:
 629  */