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Vector Packet Processing
threads.h
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1 /*
2  * Copyright (c) 2015 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 #ifndef included_vlib_threads_h
16 #define included_vlib_threads_h
17 
18 #include <vlib/main.h>
19 #include <linux/sched.h>
20 
21 extern vlib_main_t **vlib_mains;
22 
23 void vlib_set_thread_name (char *name);
24 
25 /* arg is actually a vlib__thread_t * */
26 typedef void (vlib_thread_function_t) (void *arg);
27 
29 {
30  /* constructor generated list of thread registrations */
32 
33  /* config parameters */
34  char *name;
35  char *short_name;
42 
43  /* All threads of this type run on pthreads */
48 
49 /*
50  * Frames have their cpu / vlib_main_t index in the low-order N bits
51  * Make VLIB_MAX_CPUS a power-of-two, please...
52  */
53 
54 #ifndef VLIB_MAX_CPUS
55 #define VLIB_MAX_CPUS 256
56 #endif
57 
58 #if VLIB_MAX_CPUS > CLIB_MAX_MHEAPS
59 #error Please increase number of per-cpu mheaps
60 #endif
61 
62 #define VLIB_CPU_MASK (VLIB_MAX_CPUS - 1) /* 0x3f, max */
63 #define VLIB_OFFSET_MASK (~VLIB_CPU_MASK)
64 
65 #define VLIB_LOG2_THREAD_STACK_SIZE (21)
66 #define VLIB_THREAD_STACK_SIZE (1<<VLIB_LOG2_THREAD_STACK_SIZE)
67 
68 typedef enum
69 {
72 
73 typedef struct
74 {
75  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
76  volatile u32 valid;
80 
81  /* 256 * 4 = 1024 bytes, even mult of cache line size */
82  u32 buffer_index[VLIB_FRAME_SIZE];
83 }
85 
86 typedef struct
87 {
88  /* First cache line */
89  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
90  volatile u32 *wait_at_barrier;
92 
93  /* Second Cache Line */
94  CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
95  void *thread_mheap;
97  void (*thread_function) (void *);
106  const char *barrier_caller;
107  const char *barrier_context;
109 
110  long lwp;
111  int cpu_id;
112  int core_id;
114  pthread_t thread_id;
116 
118 
119 typedef struct
120 {
121  /* enqueue side */
122  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
123  volatile u64 tail;
128 
129  /* dequeue side */
130  CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
131  volatile u64 head;
137 
138  /* dequeue hint to enqueue side */
139  CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);
140  volatile u64 head_hint;
141 
142  /* read-only, constant, shared */
143  CLIB_CACHE_LINE_ALIGN_MARK (cacheline3);
146 }
148 
149 typedef struct
150 {
154 
155 typedef struct
156 {
160 
163 
164  /* for frame queue tracing */
168 
169 typedef struct
170 {
175 
176 /* Called early, in thread 0's context */
178 
179 int vlib_frame_queue_enqueue (vlib_main_t * vm, u32 node_runtime_index,
180  u32 frame_queue_index, vlib_frame_t * frame,
181  vlib_frame_queue_msg_type_t type);
182 
183 int
185 
187 
188 void vlib_create_worker_threads (vlib_main_t * vm, int n,
189  void (*thread_function) (void *));
190 
193 
194 /* Check for a barrier sync request every 30ms */
195 #define BARRIER_SYNC_DELAY (0.030000)
196 
197 #if CLIB_DEBUG > 0
198 /* long barrier timeout, for gdb... */
199 #define BARRIER_SYNC_TIMEOUT (600.1)
200 #else
201 #define BARRIER_SYNC_TIMEOUT (1.0)
202 #endif
203 
204 #define vlib_worker_thread_barrier_sync(X) {vlib_worker_thread_barrier_sync_int(X, __FUNCTION__);}
205 
207  const char *func_name);
210 
213 {
214  return __os_thread_index;
215 }
216 
217 always_inline void
219 {
220  if (CLIB_DEBUG > 0)
221  {
222  if (vlib_get_thread_index ())
223  fformat (stderr, "%s: SMP unsafe warning...\n", __FUNCTION__);
224  }
225 }
226 
227 typedef enum
228 {
232 
233 void vlib_worker_thread_fork_fixup (vlib_fork_fixup_t which);
234 
235 #define foreach_vlib_main(body) \
236 do { \
237  vlib_main_t ** __vlib_mains = 0, *this_vlib_main; \
238  int ii; \
239  \
240  for (ii = 0; ii < vec_len (vlib_mains); ii++) \
241  { \
242  this_vlib_main = vlib_mains[ii]; \
243  ASSERT (ii == 0 || \
244  this_vlib_main->parked_at_barrier == 1); \
245  if (this_vlib_main) \
246  vec_add1 (__vlib_mains, this_vlib_main); \
247  } \
248  \
249  for (ii = 0; ii < vec_len (__vlib_mains); ii++) \
250  { \
251  this_vlib_main = __vlib_mains[ii]; \
252  /* body uses this_vlib_main... */ \
253  (body); \
254  } \
255  vec_free (__vlib_mains); \
256 } while (0);
257 
258 #define foreach_sched_policy \
259  _(SCHED_OTHER, OTHER, "other") \
260  _(SCHED_BATCH, BATCH, "batch") \
261  _(SCHED_IDLE, IDLE, "idle") \
262  _(SCHED_FIFO, FIFO, "fifo") \
263  _(SCHED_RR, RR, "rr")
264 
265 typedef enum
266 {
267 #define _(v,f,s) SCHED_POLICY_##f = v,
269 #undef _
272 
273 typedef struct
274 {
275  clib_error_t *(*vlib_launch_thread_cb) (void *fp, vlib_worker_thread_t * w,
276  unsigned cpu_id);
277  clib_error_t *(*vlib_thread_set_lcore_cb) (u32 thread, u16 cpu);
278 } vlib_thread_callbacks_t;
279 
280 typedef struct
281 {
282  /* Link list of registrations, built by constructors */
284 
285  /* Vector of registrations, w/ non-data-structure clones at the top */
287 
289 
291 
292  /*
293  * Launch all threads as pthreads,
294  * not eal_rte_launch (strict affinity) threads
295  */
297 
298  /* Number of vlib_main / vnet_main clones */
300 
301  /* Number of thread stacks to create */
303 
304  /* Number of pthreads */
306 
307  /* Number of threads */
309 
310  /* Number of cores to skip, must match the core mask */
312 
313  /* Thread prefix name */
315 
316  /* main thread lcore */
318 
319  /* Bitmap of available CPU cores */
321 
322  /* Bitmap of available CPU sockets (NUMA nodes) */
324 
325  /* Worker handoff queues */
327 
328  /* worker thread initialization barrier */
330 
331  /* scheduling policy */
333 
334  /* scheduling policy priority */
336 
337  /* callbacks */
338  vlib_thread_callbacks_t cb;
341 
343 
344 #include <vlib/global_funcs.h>
345 
346 #define VLIB_REGISTER_THREAD(x,...) \
347  __VA_ARGS__ vlib_thread_registration_t x; \
348 static void __vlib_add_thread_registration_##x (void) \
349  __attribute__((__constructor__)) ; \
350 static void __vlib_add_thread_registration_##x (void) \
351 { \
352  vlib_thread_main_t * tm = &vlib_thread_main; \
353  x.next = tm->next; \
354  tm->next = &x; \
355 } \
356 static void __vlib_rm_thread_registration_##x (void) \
357  __attribute__((__destructor__)) ; \
358 static void __vlib_rm_thread_registration_##x (void) \
359 { \
360  vlib_thread_main_t * tm = &vlib_thread_main; \
361  VLIB_REMOVE_FROM_LINKED_LIST (tm->next, &x, next); \
362 } \
363 __VA_ARGS__ vlib_thread_registration_t x
364 
367 {
368  return vlib_thread_main.n_vlib_mains - 1;
369 }
370 
373 {
374  return worker_index + 1;
375 }
376 
379 {
380  return thread_index - 1;
381 }
382 
385 {
386  return vlib_get_thread_index () - 1;
387 }
388 
389 static inline void
391 {
392  if (PREDICT_FALSE (*vlib_worker_threads->wait_at_barrier))
393  {
394  vlib_main_t *vm = vlib_get_main ();
395  u32 thread_index = vm->thread_index;
396  f64 t = vlib_time_now (vm);
397 
398  if (PREDICT_FALSE (vlib_worker_threads->barrier_elog_enabled))
399  {
400  vlib_worker_thread_t *w = vlib_worker_threads + thread_index;
401  /* *INDENT-OFF* */
402  ELOG_TYPE_DECLARE (e) = {
403  .format = "barrier-wait-thread-%d",
404  .format_args = "i4",
405  };
406  /* *INDENT-ON* */
407 
408  struct
409  {
410  u32 thread_index;
411  } __clib_packed *ed;
412 
414  w->elog_track);
415  ed->thread_index = thread_index;
416  }
417 
418  clib_atomic_fetch_add (vlib_worker_threads->workers_at_barrier, 1);
419  if (CLIB_DEBUG > 0)
420  {
421  vm = vlib_get_main ();
422  vm->parked_at_barrier = 1;
423  }
424  while (*vlib_worker_threads->wait_at_barrier)
425  ;
426 
427  /*
428  * Recompute the offset from thread-0 time.
429  * Note that vlib_time_now adds vm->time_offset, so
430  * clear it first. Save the resulting idea of "now", to
431  * see how well we're doing. See show_clock_command_fn(...)
432  */
433  {
434  f64 now;
435  vm->time_offset = 0.0;
436  now = vlib_time_now (vm);
439  }
440 
441  if (CLIB_DEBUG > 0)
442  vm->parked_at_barrier = 0;
443  clib_atomic_fetch_add (vlib_worker_threads->workers_at_barrier, -1);
444 
445  if (PREDICT_FALSE (*vlib_worker_threads->node_reforks_required))
446  {
447  if (PREDICT_FALSE (vlib_worker_threads->barrier_elog_enabled))
448  {
449  t = vlib_time_now (vm) - t;
450  vlib_worker_thread_t *w = vlib_worker_threads + thread_index;
451  /* *INDENT-OFF* */
452  ELOG_TYPE_DECLARE (e) = {
453  .format = "barrier-refork-thread-%d",
454  .format_args = "i4",
455  };
456  /* *INDENT-ON* */
457 
458  struct
459  {
460  u32 thread_index;
461  } __clib_packed *ed;
462 
464  w->elog_track);
465  ed->thread_index = thread_index;
466  }
467 
469  clib_atomic_fetch_add (vlib_worker_threads->node_reforks_required,
470  -1);
471  while (*vlib_worker_threads->node_reforks_required)
472  ;
473  }
474  if (PREDICT_FALSE (vlib_worker_threads->barrier_elog_enabled))
475  {
476  t = vlib_time_now (vm) - t;
477  vlib_worker_thread_t *w = vlib_worker_threads + thread_index;
478  /* *INDENT-OFF* */
479  ELOG_TYPE_DECLARE (e) = {
480  .format = "barrier-released-thread-%d: %dus",
481  .format_args = "i4i4",
482  };
483  /* *INDENT-ON* */
484 
485  struct
486  {
487  u32 thread_index;
488  u32 duration;
489  } __clib_packed *ed;
490 
492  w->elog_track);
493  ed->thread_index = thread_index;
494  ed->duration = (int) (1000000.0 * t);
495  }
496  }
497 }
498 
501 {
502  vlib_main_t *vm;
504  ASSERT (worker_index < tm->n_vlib_mains - 1);
505  vm = vlib_mains[worker_index + 1];
506  ASSERT (vm);
507  return vm;
508 }
509 
510 static inline u8
512 {
513  return (!vlib_num_workers ()
514  || ((vlib_get_thread_index () == 0
515  && vlib_worker_threads->wait_at_barrier[0])));
516 }
517 
518 static inline void
520 {
522  hf->valid = 1;
523 }
524 
525 static inline vlib_frame_queue_elt_t *
526 vlib_get_frame_queue_elt (u32 frame_queue_index, u32 index)
527 {
528  vlib_frame_queue_t *fq;
532  vec_elt_at_index (tm->frame_queue_mains, frame_queue_index);
533  u64 new_tail;
534 
535  fq = fqm->vlib_frame_queues[index];
536  ASSERT (fq);
537 
538  new_tail = clib_atomic_add_fetch (&fq->tail, 1);
539 
540  /* Wait until a ring slot is available */
541  while (new_tail >= fq->head_hint + fq->nelts)
543 
544  elt = fq->elts + (new_tail & (fq->nelts - 1));
545 
546  /* this would be very bad... */
547  while (elt->valid)
548  ;
549 
551  elt->last_n_vectors = elt->n_vectors = 0;
552 
553  return elt;
554 }
555 
556 static inline vlib_frame_queue_t *
558  u32 index,
559  u32 queue_hi_thresh,
561  handoff_queue_by_worker_index)
562 {
563  vlib_frame_queue_t *fq;
566  vec_elt_at_index (tm->frame_queue_mains, frame_queue_index);
567 
568  fq = handoff_queue_by_worker_index[index];
569  if (fq != (vlib_frame_queue_t *) (~0))
570  return fq;
571 
572  fq = fqm->vlib_frame_queues[index];
573  ASSERT (fq);
574 
575  if (PREDICT_FALSE (fq->tail >= (fq->head_hint + queue_hi_thresh)))
576  {
577  /* a valid entry in the array will indicate the queue has reached
578  * the specified threshold and is congested
579  */
580  handoff_queue_by_worker_index[index] = fq;
581  fq->enqueue_full_events++;
582  return fq;
583  }
584 
585  return NULL;
586 }
587 
588 static inline vlib_frame_queue_elt_t *
590  u32 vlib_worker_index,
592  handoff_queue_elt_by_worker_index)
593 {
595 
596  if (handoff_queue_elt_by_worker_index[vlib_worker_index])
597  return handoff_queue_elt_by_worker_index[vlib_worker_index];
598 
599  elt = vlib_get_frame_queue_elt (frame_queue_index, vlib_worker_index);
600 
601  handoff_queue_elt_by_worker_index[vlib_worker_index] = elt;
602 
603  return elt;
604 }
605 
606 u8 *vlib_thread_stack_init (uword thread_index);
607 int vlib_thread_cb_register (struct vlib_main_t *vm,
608  vlib_thread_callbacks_t * cb);
609 extern void *rpc_call_main_thread_cb_fn;
610 
611 void
613  args);
614 void vlib_rpc_call_main_thread (void *function, u8 * args, u32 size);
615 
616 u32 elog_global_id_for_msg_name (const char *msg_name);
617 #endif /* included_vlib_threads_h */
618 
619 /*
620  * fd.io coding-style-patch-verification: ON
621  *
622  * Local Variables:
623  * eval: (c-set-style "gnu")
624  * End:
625  */
f64 time_offset
Definition: main.h:74
vlib_main_t vlib_global_main
Definition: main.c:1931
#define CLIB_CACHE_LINE_ALIGN_MARK(mark)
Definition: cache.h:60
void vlib_worker_thread_init(vlib_worker_thread_t *w)
Definition: threads.c:552
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)
#define clib_atomic_add_fetch(a, b)
Definition: atomics.h:30
unsigned long u64
Definition: types.h:89
#define NULL
Definition: clib.h:58
static f64 vlib_time_now(vlib_main_t *vm)
Definition: main.h:255
void vlib_set_thread_name(char *name)
Definition: threads.c:182
u32 thread_index
Definition: main.h:197
void * thread_function_arg
Definition: threads.h:98
frame_queue_trace_t * frame_queue_traces
Definition: threads.h:165
elog_track_t elog_track
Definition: threads.h:100
vlib_worker_thread_t * vlib_worker_threads
Definition: threads.c:36
void vlib_rpc_call_main_thread(void *function, u8 *args, u32 size)
Definition: threads.c:1823
struct vlib_thread_registration_ * next
Definition: threads.h:31
int vlib_thread_cb_register(struct vlib_main_t *vm, vlib_thread_callbacks_t *cb)
Definition: threads.c:1799
volatile u32 valid
Definition: threads.h:76
static 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)
Definition: threads.h:557
unsigned char u8
Definition: types.h:56
static void vlib_smp_unsafe_warning(void)
Definition: threads.h:218
double f64
Definition: types.h:142
volatile int parked_at_barrier
Definition: main.h:219
static void vlib_worker_thread_barrier_check(void)
Definition: threads.h:390
vlib_thread_registration_t * next
Definition: threads.h:283
static u32 vlib_get_worker_index(u32 thread_index)
Definition: threads.h:378
#define static_always_inline
Definition: clib.h:99
#define always_inline
Definition: clib.h:98
vlib_frame_queue_msg_type_t
Definition: threads.h:68
vlib_frame_queue_elt_t ** handoff_queue_elt_by_thread_index
Definition: threads.h:151
#define vec_elt_at_index(v, i)
Get vector value at index i checking that i is in bounds.
uword * cpu_core_bitmap
Definition: threads.h:320
int vlib_frame_queue_dequeue(vlib_main_t *vm, vlib_frame_queue_main_t *fqm)
Definition: threads.c:1598
vlib_frame_queue_elt_t * elts
Definition: threads.h:144
pthread_t thread[MAX_CONNS]
Definition: main.c:142
f64 time_last_barrier_release
Definition: main.h:75
unsigned int u32
Definition: types.h:88
static u32 vlib_get_current_worker_index()
Definition: threads.h:384
#define VLIB_FRAME_SIZE
Definition: node.h:376
vlib_fork_fixup_t
Definition: threads.h:227
void vlib_process_signal_event_mt_helper(vlib_process_signal_event_mt_args_t *args)
Definition: threads.c:1812
int extern_thread_mgmt
Definition: threads.h:339
sched_policy_t
Definition: threads.h:265
void * thread_mheap
Definition: threads.h:95
volatile u64 head
Definition: threads.h:131
u8 * vlib_thread_stack_init(uword thread_index)
Definition: main.c:624
vlib_thread_callbacks_t cb
Definition: threads.h:338
const char * barrier_context
Definition: threads.h:107
unsigned short u16
Definition: types.h:57
signed long i64
Definition: types.h:78
void vlib_worker_thread_barrier_release(vlib_main_t *vm)
Definition: threads.c:1487
#define PREDICT_FALSE(x)
Definition: clib.h:111
static 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)
Definition: threads.h:589
u8 name[64]
Definition: memclnt.api:152
word fformat(FILE *f, char *fmt,...)
Definition: format.c:462
void vlib_worker_thread_node_runtime_update(void)
Definition: threads.c:1203
void vlib_worker_thread_fork_fixup(vlib_fork_fixup_t which)
Definition: threads.c:1347
volatile u64 tail
Definition: threads.h:123
vlib_frame_queue_t ** vlib_frame_queues
Definition: threads.h:161
static_always_inline uword vlib_get_thread_index(void)
Definition: threads.h:212
vlib_main_t * vm
Definition: buffer.c:312
elog_main_t elog_main
Definition: main.h:172
frame_queue_nelt_counter_t * frame_queue_histogram
Definition: threads.h:166
void * rpc_call_main_thread_cb_fn
Definition: threads.c:1820
#define ELOG_TYPE_DECLARE(f)
Definition: elog.h:439
vlib_worker_thread_t * worker_threads
Definition: threads.h:290
static u8 vlib_thread_is_main_w_barrier(void)
Definition: threads.h:511
static vlib_frame_queue_elt_t * vlib_get_frame_queue_elt(u32 frame_queue_index, u32 index)
Definition: threads.h:526
volatile u32 * wait_at_barrier
Definition: threads.h:90
vlib_frame_queue_per_thread_data_t * per_thread_data
Definition: threads.h:162
vlib_frame_queue_t ** congested_handoff_queue_by_thread_index
Definition: threads.h:152
#define ASSERT(truth)
vlib_frame_queue_main_t * frame_queue_mains
Definition: threads.h:326
#define ELOG_TRACK_DATA(em, f, track)
Definition: elog.h:475
struct vlib_thread_registration_ vlib_thread_registration_t
uword * thread_registrations_by_name
Definition: threads.h:288
u32 vlib_frame_queue_main_init(u32 node_index, u32 frame_queue_nelts)
Definition: threads.c:1760
volatile u32 * node_reforks_required
Definition: threads.h:108
const char * barrier_caller
Definition: threads.h:106
static vlib_main_t * vlib_get_main(void)
Definition: global_funcs.h:23
clib_error_t * vlib_thread_init(vlib_main_t *vm)
Definition: threads.c:237
#define clib_atomic_fetch_add(a, b)
Definition: atomics.h:23
u32 enqueue_full_events
Definition: threads.h:127
u64 uword
Definition: types.h:112
vlib_main_t ** vlib_mains
Definition: buffer.c:321
void vlib_create_worker_threads(vlib_main_t *vm, int n, void(*thread_function)(void *))
volatile u64 head_hint
Definition: threads.h:140
static void vlib_put_frame_queue_elt(vlib_frame_queue_elt_t *hf)
Definition: threads.h:519
volatile u32 * workers_at_barrier
Definition: threads.h:91
static u32 vlib_num_workers()
Definition: threads.h:366
void vlib_worker_thread_node_refork(void)
Definition: threads.c:1021
#define CLIB_MEMORY_BARRIER()
Definition: clib.h:115
uword * cpu_socket_bitmap
Definition: threads.h:323
#define foreach_sched_policy
Definition: threads.h:258
void( vlib_thread_function_t)(void *arg)
Definition: threads.h:26
u32 elog_global_id_for_msg_name(const char *msg_name)
Definition: threads.c:47
vlib_thread_registration_t ** registrations
Definition: threads.h:286
vlib_thread_main_t vlib_thread_main
Definition: threads.c:37
pthread_t thread_id
Definition: threads.h:114
vlib_thread_registration_t * registration
Definition: threads.h:102
volatile u32 worker_thread_release
Definition: threads.h:329
static vlib_main_t * vlib_get_worker_vlib_main(u32 worker_index)
Definition: threads.h:500
static u32 vlib_get_worker_thread_index(u32 worker_index)
Definition: threads.h:372
void vlib_worker_thread_barrier_sync_int(vlib_main_t *vm, const char *func_name)
Definition: threads.c:1385