aboutsummaryrefslogtreecommitdiffstats
path: root/src/vlib/threads.h
blob: fc1633f610e57e0911b1b335aa17ef390d44910f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
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
/*
 * 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 (20)
#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;

  long lwp;
  int lcore_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
{
  u32 node_index;
  vlib_frame_queue_t **vlib_frame_queues;

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

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

vlib_worker_thread_t *vlib_alloc_thread (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);

u64 dispatch_node (vlib_main_t * vm,
		   vlib_node_runtime_t * node,
		   vlib_node_type_t type,
		   vlib_node_state_t dispatch_state,
		   vlib_frame_t * frame, u64 last_time_stamp);

u64 dispatch_pending_node (vlib_main_t * vm,
			   vlib_pending_frame_t * p, u64 last_time_stamp);

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

void vlib_worker_thread_barrier_sync (vlib_main_t * vm);
void vlib_worker_thread_barrier_release (vlib_main_t * vm);

always_inline void
vlib_smp_unsafe_warning (void)
{
  if (CLIB_DEBUG > 0)
    {
      if (os_get_cpu_number ())
	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);

static inline void
vlib_worker_thread_barrier_check (void)
{
  if (PREDICT_FALSE (*vlib_worker_threads->wait_at_barrier))
    {
      clib_smp_atomic_add (vlib_worker_threads->workers_at_barrier, 1);
      while (*vlib_worker_threads->wait_at_barrier)
	;
      clib_smp_atomic_add (vlib_worker_threads->workers_at_barrier, -1);
    }
}

#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];                  \
      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 lcore_id);
  clib_error_t *(*vlib_thread_set_lcore_cb) (u32 thread, u16 lcore);
} 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 */
  u8 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;
} vlib_thread_main_t;

extern vlib_thread_main_t vlib_thread_main;

#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;                                        \
}                                                       \
__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_cpu_index (u32 worker_index)
{
  return worker_index + 1;
}

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

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

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 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 = __sync_add_and_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;
}

int vlib_thread_cb_register (struct vlib_main_t *vm,
			     vlib_thread_callbacks_t * cb);

#endif /* included_vlib_threads_h */

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