FD.io VPP  v20.01-rc2-3-g9af7a98cf
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);
211 
214 {
215  return __os_thread_index;
216 }
217 
218 always_inline void
220 {
221  if (CLIB_DEBUG > 0)
222  {
223  if (vlib_get_thread_index ())
224  fformat (stderr, "%s: SMP unsafe warning...\n", __FUNCTION__);
225  }
226 }
227 
228 typedef enum
229 {
233 
234 void vlib_worker_thread_fork_fixup (vlib_fork_fixup_t which);
235 
236 #define foreach_vlib_main(body) \
237 do { \
238  vlib_main_t ** __vlib_mains = 0, *this_vlib_main; \
239  int ii; \
240  \
241  for (ii = 0; ii < vec_len (vlib_mains); ii++) \
242  { \
243  this_vlib_main = vlib_mains[ii]; \
244  ASSERT (ii == 0 || \
245  this_vlib_main->parked_at_barrier == 1); \
246  if (this_vlib_main) \
247  vec_add1 (__vlib_mains, this_vlib_main); \
248  } \
249  \
250  for (ii = 0; ii < vec_len (__vlib_mains); ii++) \
251  { \
252  this_vlib_main = __vlib_mains[ii]; \
253  /* body uses this_vlib_main... */ \
254  (body); \
255  } \
256  vec_free (__vlib_mains); \
257 } while (0);
258 
259 #define foreach_sched_policy \
260  _(SCHED_OTHER, OTHER, "other") \
261  _(SCHED_BATCH, BATCH, "batch") \
262  _(SCHED_IDLE, IDLE, "idle") \
263  _(SCHED_FIFO, FIFO, "fifo") \
264  _(SCHED_RR, RR, "rr")
265 
266 typedef enum
267 {
268 #define _(v,f,s) SCHED_POLICY_##f = v,
270 #undef _
273 
274 typedef struct
275 {
276  clib_error_t *(*vlib_launch_thread_cb) (void *fp, vlib_worker_thread_t * w,
277  unsigned cpu_id);
278  clib_error_t *(*vlib_thread_set_lcore_cb) (u32 thread, u16 cpu);
279 } vlib_thread_callbacks_t;
280 
281 typedef struct
282 {
283  /* Link list of registrations, built by constructors */
285 
286  /* Vector of registrations, w/ non-data-structure clones at the top */
288 
290 
292 
293  /*
294  * Launch all threads as pthreads,
295  * not eal_rte_launch (strict affinity) threads
296  */
298 
299  /* Number of vlib_main / vnet_main clones */
301 
302  /* Number of thread stacks to create */
304 
305  /* Number of pthreads */
307 
308  /* Number of threads */
310 
311  /* Number of cores to skip, must match the core mask */
313 
314  /* Thread prefix name */
316 
317  /* main thread lcore */
319 
320  /* Bitmap of available CPU cores */
322 
323  /* Bitmap of available CPU sockets (NUMA nodes) */
325 
326  /* Worker handoff queues */
328 
329  /* worker thread initialization barrier */
331 
332  /* scheduling policy */
334 
335  /* scheduling policy priority */
337 
338  /* callbacks */
339  vlib_thread_callbacks_t cb;
342 
344 
345 #include <vlib/global_funcs.h>
346 
347 #define VLIB_REGISTER_THREAD(x,...) \
348  __VA_ARGS__ vlib_thread_registration_t x; \
349 static void __vlib_add_thread_registration_##x (void) \
350  __attribute__((__constructor__)) ; \
351 static void __vlib_add_thread_registration_##x (void) \
352 { \
353  vlib_thread_main_t * tm = &vlib_thread_main; \
354  x.next = tm->next; \
355  tm->next = &x; \
356 } \
357 static void __vlib_rm_thread_registration_##x (void) \
358  __attribute__((__destructor__)) ; \
359 static void __vlib_rm_thread_registration_##x (void) \
360 { \
361  vlib_thread_main_t * tm = &vlib_thread_main; \
362  VLIB_REMOVE_FROM_LINKED_LIST (tm->next, &x, next); \
363 } \
364 __VA_ARGS__ vlib_thread_registration_t x
365 
368 {
369  return vlib_thread_main.n_vlib_mains - 1;
370 }
371 
374 {
375  return worker_index + 1;
376 }
377 
380 {
381  return thread_index - 1;
382 }
383 
386 {
387  return vlib_get_thread_index () - 1;
388 }
389 
390 static inline void
392 {
393  if (PREDICT_FALSE (*vlib_worker_threads->wait_at_barrier))
394  {
395  vlib_main_t *vm = vlib_get_main ();
396  u32 thread_index = vm->thread_index;
397  f64 t = vlib_time_now (vm);
398 
399  if (PREDICT_FALSE (vlib_worker_threads->barrier_elog_enabled))
400  {
401  vlib_worker_thread_t *w = vlib_worker_threads + thread_index;
402  /* *INDENT-OFF* */
403  ELOG_TYPE_DECLARE (e) = {
404  .format = "barrier-wait-thread-%d",
405  .format_args = "i4",
406  };
407  /* *INDENT-ON* */
408 
409  struct
410  {
411  u32 thread_index;
412  } __clib_packed *ed;
413 
415  w->elog_track);
416  ed->thread_index = thread_index;
417  }
418 
419  if (CLIB_DEBUG > 0)
420  {
421  vm = vlib_get_main ();
422  vm->parked_at_barrier = 1;
423  }
424  clib_atomic_fetch_add (vlib_worker_threads->workers_at_barrier, 1);
425  while (*vlib_worker_threads->wait_at_barrier)
426  ;
427 
428  /*
429  * Recompute the offset from thread-0 time.
430  * Note that vlib_time_now adds vm->time_offset, so
431  * clear it first. Save the resulting idea of "now", to
432  * see how well we're doing. See show_clock_command_fn(...)
433  */
434  {
435  f64 now;
436  vm->time_offset = 0.0;
437  now = vlib_time_now (vm);
440  }
441 
442  if (CLIB_DEBUG > 0)
443  vm->parked_at_barrier = 0;
444  clib_atomic_fetch_add (vlib_worker_threads->workers_at_barrier, -1);
445 
446  if (PREDICT_FALSE (*vlib_worker_threads->node_reforks_required))
447  {
448  if (PREDICT_FALSE (vlib_worker_threads->barrier_elog_enabled))
449  {
450  t = vlib_time_now (vm) - t;
451  vlib_worker_thread_t *w = vlib_worker_threads + thread_index;
452  /* *INDENT-OFF* */
453  ELOG_TYPE_DECLARE (e) = {
454  .format = "barrier-refork-thread-%d",
455  .format_args = "i4",
456  };
457  /* *INDENT-ON* */
458 
459  struct
460  {
461  u32 thread_index;
462  } __clib_packed *ed;
463 
465  w->elog_track);
466  ed->thread_index = thread_index;
467  }
468 
470  clib_atomic_fetch_add (vlib_worker_threads->node_reforks_required,
471  -1);
472  while (*vlib_worker_threads->node_reforks_required)
473  ;
474  }
475  if (PREDICT_FALSE (vlib_worker_threads->barrier_elog_enabled))
476  {
477  t = vlib_time_now (vm) - t;
478  vlib_worker_thread_t *w = vlib_worker_threads + thread_index;
479  /* *INDENT-OFF* */
480  ELOG_TYPE_DECLARE (e) = {
481  .format = "barrier-released-thread-%d: %dus",
482  .format_args = "i4i4",
483  };
484  /* *INDENT-ON* */
485 
486  struct
487  {
488  u32 thread_index;
489  u32 duration;
490  } __clib_packed *ed;
491 
493  w->elog_track);
494  ed->thread_index = thread_index;
495  ed->duration = (int) (1000000.0 * t);
496  }
497  }
498 }
499 
502 {
503  vlib_main_t *vm;
505  ASSERT (worker_index < tm->n_vlib_mains - 1);
506  vm = vlib_mains[worker_index + 1];
507  ASSERT (vm);
508  return vm;
509 }
510 
511 static inline u8
513 {
514  return (!vlib_num_workers ()
515  || ((vlib_get_thread_index () == 0
516  && vlib_worker_threads->wait_at_barrier[0])));
517 }
518 
519 static inline void
521 {
523  hf->valid = 1;
524 }
525 
526 static inline vlib_frame_queue_elt_t *
527 vlib_get_frame_queue_elt (u32 frame_queue_index, u32 index)
528 {
529  vlib_frame_queue_t *fq;
533  vec_elt_at_index (tm->frame_queue_mains, frame_queue_index);
534  u64 new_tail;
535 
536  fq = fqm->vlib_frame_queues[index];
537  ASSERT (fq);
538 
539  new_tail = clib_atomic_add_fetch (&fq->tail, 1);
540 
541  /* Wait until a ring slot is available */
542  while (new_tail >= fq->head_hint + fq->nelts)
544 
545  elt = fq->elts + (new_tail & (fq->nelts - 1));
546 
547  /* this would be very bad... */
548  while (elt->valid)
549  ;
550 
552  elt->last_n_vectors = elt->n_vectors = 0;
553 
554  return elt;
555 }
556 
557 static inline vlib_frame_queue_t *
559  u32 index,
560  u32 queue_hi_thresh,
562  handoff_queue_by_worker_index)
563 {
564  vlib_frame_queue_t *fq;
567  vec_elt_at_index (tm->frame_queue_mains, frame_queue_index);
568 
569  fq = handoff_queue_by_worker_index[index];
570  if (fq != (vlib_frame_queue_t *) (~0))
571  return fq;
572 
573  fq = fqm->vlib_frame_queues[index];
574  ASSERT (fq);
575 
576  if (PREDICT_FALSE (fq->tail >= (fq->head_hint + queue_hi_thresh)))
577  {
578  /* a valid entry in the array will indicate the queue has reached
579  * the specified threshold and is congested
580  */
581  handoff_queue_by_worker_index[index] = fq;
582  fq->enqueue_full_events++;
583  return fq;
584  }
585 
586  return NULL;
587 }
588 
589 static inline vlib_frame_queue_elt_t *
591  u32 vlib_worker_index,
593  handoff_queue_elt_by_worker_index)
594 {
596 
597  if (handoff_queue_elt_by_worker_index[vlib_worker_index])
598  return handoff_queue_elt_by_worker_index[vlib_worker_index];
599 
600  elt = vlib_get_frame_queue_elt (frame_queue_index, vlib_worker_index);
601 
602  handoff_queue_elt_by_worker_index[vlib_worker_index] = elt;
603 
604  return elt;
605 }
606 
607 u8 *vlib_thread_stack_init (uword thread_index);
608 int vlib_thread_cb_register (struct vlib_main_t *vm,
609  vlib_thread_callbacks_t * cb);
610 extern void *rpc_call_main_thread_cb_fn;
611 
612 void
614  args);
615 void vlib_rpc_call_main_thread (void *function, u8 * args, u32 size);
616 #endif /* included_vlib_threads_h */
617 
618 /*
619  * fd.io coding-style-patch-verification: ON
620  *
621  * Local Variables:
622  * eval: (c-set-style "gnu")
623  * End:
624  */
f64 time_offset
Definition: main.h:89
vlib_main_t vlib_global_main
Definition: main.c:1943
#define CLIB_CACHE_LINE_ALIGN_MARK(mark)
Definition: cache.h:60
void vlib_worker_thread_init(vlib_worker_thread_t *w)
Definition: threads.c:526
void() vlib_thread_function_t(void *arg)
Definition: threads.h:26
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
void vlib_worker_thread_initial_barrier_sync_and_release(vlib_main_t *vm)
Definition: threads.c:1369
#define NULL
Definition: clib.h:58
static f64 vlib_time_now(vlib_main_t *vm)
Definition: main.h:279
void vlib_set_thread_name(char *name)
Definition: threads.c:155
u32 thread_index
Definition: main.h:218
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:37
void vlib_rpc_call_main_thread(void *function, u8 *args, u32 size)
Definition: threads.c:1826
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:1802
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:558
unsigned char u8
Definition: types.h:56
static void vlib_smp_unsafe_warning(void)
Definition: threads.h:219
double f64
Definition: types.h:142
volatile int parked_at_barrier
Definition: main.h:243
static void vlib_worker_thread_barrier_check(void)
Definition: threads.h:391
vlib_thread_registration_t * next
Definition: threads.h:284
static u32 vlib_get_worker_index(u32 thread_index)
Definition: threads.h:379
#define static_always_inline
Definition: clib.h:99
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:321
int vlib_frame_queue_dequeue(vlib_main_t *vm, vlib_frame_queue_main_t *fqm)
Definition: threads.c:1595
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:90
unsigned int u32
Definition: types.h:88
static u32 vlib_get_current_worker_index()
Definition: threads.h:385
#define VLIB_FRAME_SIZE
Definition: node.h:378
u32 cpu_id
Definition: vpe.api:222
vlib_fork_fixup_t
Definition: threads.h:228
void vlib_process_signal_event_mt_helper(vlib_process_signal_event_mt_args_t *args)
Definition: threads.c:1815
vl_api_fib_path_type_t type
Definition: fib_types.api:123
int extern_thread_mgmt
Definition: threads.h:340
sched_policy_t
Definition: threads.h:266
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:657
vlib_thread_callbacks_t cb
Definition: threads.h:339
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:1484
#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:590
#define always_inline
Definition: ipsec.h:28
vlib_main_t * vm
Definition: in2out_ed.c:1810
word fformat(FILE *f, char *fmt,...)
Definition: format.c:462
void vlib_worker_thread_node_runtime_update(void)
Definition: threads.c:1187
void vlib_worker_thread_fork_fixup(vlib_fork_fixup_t which)
Definition: threads.c:1331
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:213
elog_main_t elog_main
Definition: main.h:193
frame_queue_nelt_counter_t * frame_queue_histogram
Definition: threads.h:166
void * rpc_call_main_thread_cb_fn
Definition: threads.c:1823
#define ELOG_TYPE_DECLARE(f)
Definition: elog.h:442
string name[64]
Definition: ip.api:44
vlib_worker_thread_t * worker_threads
Definition: threads.h:291
static u8 vlib_thread_is_main_w_barrier(void)
Definition: threads.h:512
static vlib_frame_queue_elt_t * vlib_get_frame_queue_elt(u32 frame_queue_index, u32 index)
Definition: threads.h:527
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:327
#define ELOG_TRACK_DATA(em, f, track)
Definition: elog.h:478
struct vlib_thread_registration_ vlib_thread_registration_t
uword * thread_registrations_by_name
Definition: threads.h:289
u32 vlib_frame_queue_main_init(u32 node_index, u32 frame_queue_nelts)
Definition: threads.c:1763
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:210
#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:332
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:520
volatile u32 * workers_at_barrier
Definition: threads.h:91
static u32 vlib_num_workers()
Definition: threads.h:367
void vlib_worker_thread_node_refork(void)
Definition: threads.c:1001
vlib_main_t vlib_node_runtime_t vlib_frame_t * frame
Definition: in2out_ed.c:1811
#define CLIB_MEMORY_BARRIER()
Definition: clib.h:115
uword * cpu_socket_bitmap
Definition: threads.h:324
#define foreach_sched_policy
Definition: threads.h:259
vlib_thread_registration_t ** registrations
Definition: threads.h:287
vlib_thread_main_t vlib_thread_main
Definition: threads.c:38
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:330
static vlib_main_t * vlib_get_worker_vlib_main(u32 worker_index)
Definition: threads.h:501
static u32 vlib_get_worker_thread_index(u32 worker_index)
Definition: threads.h:373
void vlib_worker_thread_barrier_sync_int(vlib_main_t *vm, const char *func_name)
Definition: threads.c:1394