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path: root/src/vlib/threads.h
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ef='#n355'>355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631
/*
 * Copyright (c) 2015 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#ifndef included_vlib_threads_h
#define included_vlib_threads_h

#include <vlib/main.h>
#include <linux/sched.h>

extern vlib_main_t **vlib_mains;

void vlib_set_thread_name (char *name);

/* arg is actually a vlib__thread_t * */
typedef void (vlib_thread_function_t) (void *arg);

typedef struct vlib_thread_registration_
{
  /* constructor generated list of thread registrations */
  struct vlib_thread_registration_ *next;

  /* config parameters */
  char *name;
  char *short_name;
  vlib_thread_function_t *function;
  uword mheap_size;
  int fixed_count;
  u32 count;
  int no_data_structure_clone;
  u32 frame_queue_nelts;

  /* All threads of this type run on pthreads */
  int use_pthreads;
  u32 first_index;
  uword *coremask;
} vlib_thread_registration_t;

/*
 * Frames have their cpu / vlib_main_t index in the low-order N bits
 * Make VLIB_MAX_CPUS a power-of-two, please...
 */

#ifndef VLIB_MAX_CPUS
#define VLIB_MAX_CPUS 256
#endif

#if VLIB_MAX_CPUS > CLIB_MAX_MHEAPS
#error Please increase number of per-cpu mheaps
#endif

#define VLIB_CPU_MASK (VLIB_MAX_CPUS - 1)	/* 0x3f, max */
#define VLIB_OFFSET_MASK (~VLIB_CPU_MASK)

#define VLIB_LOG2_THREAD_STACK_SIZE (21)
#define VLIB_THREAD_STACK_SIZE (1<<VLIB_LOG2_THREAD_STACK_SIZE)

typedef enum
{
  VLIB_FRAME_QUEUE_ELT_DISPATCH_FRAME,
} vlib_frame_queue_msg_type_t;

typedef struct
{
  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
  volatile u32 valid;
  u32 msg_type;
  u32 n_vectors;
  u32 last_n_vectors;

  /* 256 * 4 = 1024 bytes, even mult of cache line size */
  u32 buffer_index[VLIB_FRAME_SIZE];
}
vlib_frame_queue_elt_t;

typedef struct
{
  /* First cache line */
  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
  volatile u32 *wait_at_barrier;
  volatile u32 *workers_at_barrier;

  /* Second Cache Line */
    CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
  void *thread_mheap;
  u8 *thread_stack;
  void (*thread_function) (void *);
  void *thread_function_arg;
  i64 recursion_level;
  elog_track_t elog_track;
  u32 instance_id;
  vlib_thread_registration_t *registration;
  u8 *name;
  u64 barrier_sync_count;
  u8 barrier_elog_enabled;
  const char *barrier_caller;
  const char *barrier_context;
  volatile u32 *node_reforks_required;

  long lwp;
  int cpu_id;
  int core_id;
  int numa_id;
  pthread_t thread_id;
} vlib_worker_thread_t;

extern vlib_worker_thread_t *vlib_worker_threads;

typedef struct
{
  /* enqueue side */
  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
  volatile u64 tail;
  u64 enqueues;
  u64 enqueue_ticks;
  u64 enqueue_vectors;
  u32 enqueue_full_events;

  /* dequeue side */
    CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
  volatile u64 head;
  u64 dequeues;
  u64 dequeue_ticks;
  u64 dequeue_vectors;
  u64 trace;
  u64 vector_threshold;

  /* dequeue hint to enqueue side */
    CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);
  volatile u64 head_hint;

  /* read-only, constant, shared */
    CLIB_CACHE_LINE_ALIGN_MARK (cacheline3);
  vlib_frame_queue_elt_t *elts;
  u32 nelts;
}
vlib_frame_queue_t;

typedef struct
{
  vlib_frame_queue_elt_t **handoff_queue_elt_by_thread_index;
  vlib_frame_queue_t **congested_handoff_queue_by_thread_index;
} vlib_frame_queue_per_thread_data_t;

typedef struct
{
  u32 node_index;
  u32 frame_queue_nelts;
  u32 queue_hi_thresh;

  vlib_frame_queue_t **vlib_frame_queues;
  vlib_frame_queue_per_thread_data_t *per_thread_data;

  /* for frame queue tracing */
  frame_queue_trace_t *frame_queue_traces;
  frame_queue_nelt_counter_t *frame_queue_histogram;
} vlib_frame_queue_main_t;

typedef struct
{
  uword node_index;
  uword type_opaque;
  uword data;
} vlib_process_signal_event_mt_args_t;

/* Called early, in thread 0's context */
clib_error_t *vlib_thread_init (vlib_main_t * vm);

int vlib_frame_queue_enqueue (vlib_main_t * vm, u32 node_runtime_index,
			      u32 frame_queue_index, vlib_frame_t * frame,
			      vlib_frame_queue_msg_type_t type);

int
vlib_frame_queue_dequeue (vlib_main_t * vm, vlib_frame_queue_main_t * fqm);

void vlib_worker_thread_node_runtime_update (void);

void vlib_create_worker_threads (vlib_main_t * vm, int n,
				 void (*thread_function) (void *));

void vlib_worker_thread_init (vlib_worker_thread_t * w);
u32 vlib_frame_queue_main_init (u32 node_index, u32 frame_queue_nelts);

/* Check for a barrier sync request every 30ms */
#define BARRIER_SYNC_DELAY (0.030000)

#if CLIB_DEBUG > 0
/* long barrier timeout, for gdb... */
#define BARRIER_SYNC_TIMEOUT (600.1)
#else
#define BARRIER_SYNC_TIMEOUT (1.0)
#endif

#define vlib_worker_thread_barrier_sync(X) {vlib_worker_thread_barrier_sync_int(X, __FUNCTION__);}

void vlib_worker_thread_barrier_sync_int (vlib_main_t * vm,
					  const char *func_name);
void vlib_worker_thread_barrier_release (vlib_main_t * vm);
void vlib_worker_thread_initial_barrier_sync_and_release (vlib_main_t * vm);
void vlib_worker_thread_node_refork (void);

static_always_inline uword
vlib_get_thread_index (void)
{
  return __os_thread_index;
}

always_inline void
vlib_smp_unsafe_warning (void)
{
  if (CLIB_DEBUG > 0)
    {
      if (vlib_get_thread_index ())
	fformat (stderr, "%s: SMP unsafe warning...\n", __FUNCTION__);
    }
}

typedef enum
{
  VLIB_WORKER_THREAD_FORK_FIXUP_ILLEGAL = 0,
  VLIB_WORKER_THREAD_FORK_FIXUP_NEW_SW_IF_INDEX,
} vlib_fork_fixup_t;

void vlib_worker_thread_fork_fixup (vlib_fork_fixup_t which);

#define foreach_vlib_main(body)                         \
do {                                                    \
  vlib_main_t ** __vlib_mains = 0, *this_vlib_main;     \
  int ii;                                               \
                                                        \
  for (ii = 0; ii < vec_len (vlib_mains); ii++)         \
    {                                                   \
      this_vlib_main = vlib_mains[ii];                  \
      ASSERT (ii == 0 ||                                \
	      this_vlib_main->parked_at_barrier == 1);  \
      if (this_vlib_main)                               \
        vec_add1 (__vlib_mains, this_vlib_main);        \
    }                                                   \
                                                        \
  for (ii = 0; ii < vec_len (__vlib_mains); ii++)       \
    {                                                   \
      this_vlib_main = __vlib_mains[ii];                \
      /* body uses this_vlib_main... */                 \
      (body);                                           \
    }                                                   \
  vec_free (__vlib_mains);                              \
} while (0);

#define foreach_sched_policy \
  _(SCHED_OTHER, OTHER, "other") \
  _(SCHED_BATCH, BATCH, "batch") \
  _(SCHED_IDLE, IDLE, "idle")   \
  _(SCHED_FIFO, FIFO, "fifo")   \
  _(SCHED_RR, RR, "rr")

typedef enum
{
#define _(v,f,s) SCHED_POLICY_##f = v,
  foreach_sched_policy
#undef _
    SCHED_POLICY_N,
} sched_policy_t;

typedef struct
{
  clib_error_t *(*vlib_launch_thread_cb) (void *fp, vlib_worker_thread_t * w,
					  unsigned cpu_id);
  clib_error_t *(*vlib_thread_set_lcore_cb) (u32 thread, u16 cpu);
} vlib_thread_callbacks_t;

typedef struct
{
  /* Link list of registrations, built by constructors */
  vlib_thread_registration_t *next;

  /* Vector of registrations, w/ non-data-structure clones at the top */
  vlib_thread_registration_t **registrations;

  uword *thread_registrations_by_name;

  vlib_worker_thread_t *worker_threads;

  /*
   * Launch all threads as pthreads,
   * not eal_rte_launch (strict affinity) threads
   */
  int use_pthreads;

  /* Number of vlib_main / vnet_main clones */
  u32 n_vlib_mains;

  /* Number of thread stacks to create */
  u32 n_thread_stacks;

  /* Number of pthreads */
  u32 n_pthreads;

  /* Number of threads */
  u32 n_threads;

  /* Number of cores to skip, must match the core mask */
  u32 skip_cores;

  /* Thread prefix name */
  u8 *thread_prefix;

  /* main thread lcore */
  u32 main_lcore;

  /* Bitmap of available CPU cores */
  uword *cpu_core_bitmap;

  /* Bitmap of available CPU sockets (NUMA nodes) */
  uword *cpu_socket_bitmap;

  /* Worker handoff queues */
  vlib_frame_queue_main_t *frame_queue_mains;

  /* worker thread initialization barrier */
  volatile u32 worker_thread_release;

  /* scheduling policy */
  u32 sched_policy;

  /* scheduling policy priority */
  u32 sched_priority;

  /* callbacks */
  vlib_thread_callbacks_t cb;
  int extern_thread_mgmt;

  /* NUMA-bound heap size */
  uword numa_heap_size;

} vlib_thread_main_t;

extern vlib_thread_main_t vlib_thread_main;

#include <vlib/global_funcs.h>

#define VLIB_REGISTER_THREAD(x,...)                     \
  __VA_ARGS__ vlib_thread_registration_t x;             \
static void __vlib_add_thread_registration_##x (void)   \
  __attribute__((__constructor__)) ;                    \
static void __vlib_add_thread_registration_##x (void)   \
{                                                       \
  vlib_thread_main_t * tm = &vlib_thread_main;          \
  x.next = tm->next;                                    \
  tm->next = &x;                                        \
}                                                       \
static void __vlib_rm_thread_registration_##x (void)    \
  __attribute__((__destructor__)) ;                     \
static void __vlib_rm_thread_registration_##x (void)    \
{                                                       \
  vlib_thread_main_t * tm = &vlib_thread_main;          \
  VLIB_REMOVE_FROM_LINKED_LIST (tm->next, &x, next);    \
}                                                       \
__VA_ARGS__ vlib_thread_registration_t x

always_inline u32
vlib_num_workers ()
{
  return vlib_thread_main.n_vlib_mains - 1;
}

always_inline u32
vlib_get_worker_thread_index (u32 worker_index)
{
  return worker_index + 1;
}

always_inline u32
vlib_get_worker_index (u32 thread_index)
{
  return thread_index - 1;
}

always_inline u32
vlib_get_current_worker_index ()
{
  return vlib_get_thread_index () - 1;
}

static inline void
vlib_worker_thread_barrier_check (void)
{
  if (PREDICT_FALSE (*vlib_worker_threads->wait_at_barrier))
    {
      vlib_main_t *vm = vlib_get_main ();
      u32 thread_index = vm->thread_index;
      f64 t = vlib_time_now (vm);

      if (PREDICT_FALSE (vlib_worker_threads->barrier_elog_enabled))
	{
	  vlib_worker_thread_t *w = vlib_worker_threads + thread_index;
	  /* *INDENT-OFF* */
	  ELOG_TYPE_DECLARE (e) = {
	    .format = "barrier-wait-thread-%d",
	    .format_args = "i4",
	  };
	  /* *INDENT-ON* */

	  struct
	  {
	    u32 thread_index;
	  } __clib_packed *ed;

	  ed = ELOG_TRACK_DATA (&vlib_global_main.elog_main, e,
				w->elog_track);
	  ed->thread_index = thread_index;
	}

      if (CLIB_DEBUG > 0)
	{
	  vm = vlib_get_main ();
	  vm->parked_at_barrier = 1;
	}
      clib_atomic_fetch_add (vlib_worker_threads->workers_at_barrier, 1);
      while (*vlib_worker_threads->wait_at_barrier)
	;

      /*
       * Recompute the offset from thread-0 time.
       * Note that vlib_time_now adds vm->time_offset, so
       * clear it first. Save the resulting idea of "now", to
       * see how well we're doing. See show_clock_command_fn(...)
       */
      {
	f64 now;
	vm->time_offset = 0.0;
	now = vlib_time_now (vm);
	vm->time_offset = vlib_global_main.time_last_barrier_release - now;
	vm->time_last_barrier_release = vlib_time_now (vm);
      }

      if (CLIB_DEBUG > 0)
	vm->parked_at_barrier = 0;
      clib_atomic_fetch_add (vlib_worker_threads->workers_at_barrier, -1);

      if (PREDICT_FALSE (*vlib_worker_threads->node_reforks_required))
	{
	  if (PREDICT_FALSE (vlib_worker_threads->barrier_elog_enabled))
	    {
	      t = vlib_time_now (vm) - t;
	      vlib_worker_thread_t *w = vlib_worker_threads + thread_index;
              /* *INDENT-OFF* */
              ELOG_TYPE_DECLARE (e) = {
                .format = "barrier-refork-thread-%d",
                .format_args = "i4",
              };
              /* *INDENT-ON* */

	      struct
	      {
		u32 thread_index;
	      } __clib_packed *ed;

	      ed = ELOG_TRACK_DATA (&vlib_global_main.elog_main, e,
				    w->elog_track);
	      ed->thread_index = thread_index;
	    }

	  vlib_worker_thread_node_refork ();
	  clib_atomic_fetch_add (vlib_worker_threads->node_reforks_required,
				 -1);
	  while (*vlib_worker_threads->node_reforks_required)
	    ;
	}
      if (PREDICT_FALSE (vlib_worker_threads->barrier_elog_enabled))
	{
	  t = vlib_time_now (vm) - t;
	  vlib_worker_thread_t *w = vlib_worker_threads + thread_index;
	  /* *INDENT-OFF* */
	  ELOG_TYPE_DECLARE (e) = {
	    .format = "barrier-released-thread-%d: %dus",
	    .format_args = "i4i4",
	  };
	  /* *INDENT-ON* */

	  struct
	  {
	    u32 thread_index;
	    u32 duration;
	  } __clib_packed *ed;

	  ed = ELOG_TRACK_DATA (&vlib_global_main.elog_main, e,
				w->elog_track);
	  ed->thread_index = thread_index;
	  ed->duration = (int) (1000000.0 * t);
	}
    }
}

always_inline vlib_main_t *
vlib_get_worker_vlib_main (u32 worker_index)
{
  vlib_main_t *vm;
  vlib_thread_main_t *tm = &vlib_thread_main;
  ASSERT (worker_index < tm->n_vlib_mains - 1);
  vm = vlib_mains[worker_index + 1];
  ASSERT (vm);
  return vm;
}

static inline u8
vlib_thread_is_main_w_barrier (void)
{
  return (!vlib_num_workers ()
	  || ((vlib_get_thread_index () == 0
	       && vlib_worker_threads->wait_at_barrier[0])));
}

static inline void
vlib_put_frame_queue_elt (vlib_frame_queue_elt_t * hf)
{
  CLIB_MEMORY_BARRIER ();
  hf->valid = 1;
}

static inline vlib_frame_queue_elt_t *
vlib_get_frame_queue_elt (u32 frame_queue_index, u32 index)
{
  vlib_frame_queue_t *fq;
  vlib_frame_queue_elt_t *elt;
  vlib_thread_main_t *tm = &vlib_thread_main;
  vlib_frame_queue_main_t *fqm =
    vec_elt_at_index (tm->frame_queue_mains, frame_queue_index);
  u64 new_tail;

  fq = fqm->vlib_frame_queues[index];
  ASSERT (fq);

  new_tail = clib_atomic_add_fetch (&fq->tail, 1);

  /* Wait until a ring slot is available */
  while (new_tail >= fq->head_hint + fq->nelts)
    vlib_worker_thread_barrier_check ();

  elt = fq->elts + (new_tail & (fq->nelts - 1));

  /* this would be very bad... */
  while (elt->valid)
    ;

  elt->msg_type = VLIB_FRAME_QUEUE_ELT_DISPATCH_FRAME;
  elt->last_n_vectors = elt->n_vectors = 0;

  return elt;
}

static inline vlib_frame_queue_t *
is_vlib_frame_queue_congested (u32 frame_queue_index,
			       u32 index,
			       u32 queue_hi_thresh,
			       vlib_frame_queue_t **
			       handoff_queue_by_worker_index)
{
  vlib_frame_queue_t *fq;
  vlib_thread_main_t *tm = &vlib_thread_main;
  vlib_frame_queue_main_t *fqm =
    vec_elt_at_index (tm->frame_queue_mains, frame_queue_index);

  fq = handoff_queue_by_worker_index[index];
  if (fq != (vlib_frame_queue_t *) (~0))
    return fq;

  fq = fqm->vlib_frame_queues[index];
  ASSERT (fq);

  if (PREDICT_FALSE (fq->tail >= (fq->head_hint + queue_hi_thresh)))
    {
      /* a valid entry in the array will indicate the queue has reached
       * the specified threshold and is congested
       */
      handoff_queue_by_worker_index[index] = fq;
      fq->enqueue_full_events++;
      return fq;
    }

  return NULL;
}

static inline vlib_frame_queue_elt_t *
vlib_get_worker_handoff_queue_elt (u32 frame_queue_index,
				   u32 vlib_worker_index,
				   vlib_frame_queue_elt_t **
				   handoff_queue_elt_by_worker_index)
{
  vlib_frame_queue_elt_t *elt;

  if (handoff_queue_elt_by_worker_index[vlib_worker_index])
    return handoff_queue_elt_by_worker_index[vlib_worker_index];

  elt = vlib_get_frame_queue_elt (frame_queue_index, vlib_worker_index);

  handoff_queue_elt_by_worker_index[vlib_worker_index] = elt;

  return elt;
}

u8 *vlib_thread_stack_init (uword thread_index);
int vlib_thread_cb_register (struct vlib_main_t *vm,
			     vlib_thread_callbacks_t * cb);
extern void *rpc_call_main_thread_cb_fn;

void
vlib_process_signal_event_mt_helper (vlib_process_signal_event_mt_args_t *
				     args);
void vlib_rpc_call_main_thread (void *function, u8 * args, u32 size);
void vlib_get_thread_core_numa (vlib_worker_thread_t * w, unsigned cpu_id);


#endif /* included_vlib_threads_h */

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */