aboutsummaryrefslogtreecommitdiffstats
path: root/src/vppinfra/test_rwlock.c
blob: 8b6f927d63ed02cc1160b688f71a3c4399086efd (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
/*
 * Copyright (c) 2019 Arm Limited.
 * 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 _GNU_SOURCE
#define _GNU_SOURCE
#endif

#include <vppinfra/mem.h>
#include <vppinfra/cache.h>
#include <vppinfra/lock.h>
#include <pthread.h>
#include <vppinfra/format.h>
#include <vppinfra/error.h>
#include <vppinfra/time.h>
#include <sched.h>
#include <vppinfra/atomics.h>

static u32 all_threads_online = 0;

typedef struct
{
  uword threads_per_core;
  uword cpu_mask_read;
  uword read_cores;
  uword cpu_mask_write;
  uword write_cores;
  uword increment_per_thread;
  clib_rwlock_t rwlock;
  uword shared_count;
  uword iterations;
} rwlock_test_main_t;

void *
write_shared_counter (void *arg)
{
  f64 *time = vec_new (f64, 1);
  *time = 0;
  rwlock_test_main_t *rtm = arg;

  /* Wait for all threads to be created */
  while (!clib_atomic_load_acq_n (&all_threads_online));

  f64 start = clib_cpu_time_now ();
  for (uword i = 0; i < rtm->increment_per_thread; i++)
    {
      clib_rwlock_writer_lock (&rtm->rwlock);
      rtm->shared_count++;
      clib_rwlock_writer_unlock (&rtm->rwlock);
    }
  *time = clib_cpu_time_now () - start;
  return time;
}

void *
read_shared_counter (void *arg)
{
  f64 *time = vec_new (f64, 1);
  *time = 0;
  rwlock_test_main_t *rtm = arg;
  uword cnt_cpy = 0, exp = rtm->increment_per_thread * rtm->write_cores *
    rtm->threads_per_core;

  /* Wait for all threads to be created */
  while (!clib_atomic_load_acq_n (&all_threads_online));

  f64 start = clib_cpu_time_now ();
  while (cnt_cpy < exp)
    {
      clib_rwlock_reader_lock (&rtm->rwlock);
      cnt_cpy = rtm->shared_count;
      clib_rwlock_reader_unlock (&rtm->rwlock);
    }
  *time = clib_cpu_time_now () - start;
  return time;
}

unsigned
test_rwlock (rwlock_test_main_t * rtm, f64 * elapse_time)
{
  int error = 0, total_threads = (rtm->read_cores + rtm->write_cores)
    * rtm->threads_per_core;
  pthread_t pthread[total_threads];

  cpu_set_t cpuset;
  unsigned cores_set = 0, cpu_id = 0;

  /* Spawn reader (consumer) threads */
  for (unsigned cpu_mask = rtm->cpu_mask_read; cpu_mask; cpu_mask >>= 1)
    {
      if (!(cpu_mask & 1))
	{
	  cpu_id++;
	  continue;
	}

      CPU_ZERO (&cpuset);
      CPU_SET (cpu_id, &cpuset);
      for (uword t_num = 0; t_num < rtm->threads_per_core; t_num++)
	{
	  uword t_index = cores_set * rtm->threads_per_core + t_num;
	  if (error = pthread_create (&pthread[t_index], NULL,
				      &read_shared_counter, rtm))
	    clib_unix_warning ("pthread_create failed with %d", error);

	  if (error = pthread_setaffinity_np (pthread[t_index],
					      sizeof (cpu_set_t), &cpuset))
	    clib_unix_warning ("pthread_set_affinity_np failed with %d",
			       error);
	}
      cores_set++;
      cpu_id++;
    }

  /* Spawn writer (producer) threads */
  cpu_id = 0;
  for (unsigned cpu_mask = rtm->cpu_mask_write; cpu_mask; cpu_mask >>= 1)
    {
      if (!(cpu_mask & 1))
	{
	  cpu_id++;
	  continue;
	}

      CPU_ZERO (&cpuset);
      CPU_SET (cpu_id, &cpuset);
      for (uword t_num = 0; t_num < rtm->threads_per_core; t_num++)
	{
	  uword t_index = cores_set * rtm->threads_per_core + t_num;
	  if (error = pthread_create (&pthread[t_index], NULL,
				      &write_shared_counter, rtm))
	    clib_unix_warning ("pthread_create failed with %d", error);

	  if (error = pthread_setaffinity_np (pthread[t_index],
					      sizeof (cpu_set_t), &cpuset))
	    clib_unix_warning ("pthread_set_affinity_np failed with %d",
			       error);
	}
      cores_set++;
      cpu_id++;
    }

  /* Launch all threads */
  clib_atomic_store_rel_n (&all_threads_online, 1);

  for (uword thread_num = 0; thread_num < total_threads; thread_num++)
    {
      f64 *time;
      if (error = pthread_join (pthread[thread_num], (void *) &time))
	clib_unix_warning ("pthread_join failed with %d", error);
      *elapse_time += *time;
      vec_free (time);
    }

  fformat (stdout, "Time elapsed: %.4e\n", *elapse_time);
  return rtm->shared_count;
}

uword
num_cores_in_cpu_mask (uword mask)
{
  uword num_cores = 0;
  for (uword cpu_mask = mask; cpu_mask; cpu_mask >>= 1)
    num_cores += (cpu_mask & 1);
  return num_cores;
}

int
test_rwlock_main (unformat_input_t * i)
{
  rwlock_test_main_t _rtm, *rtm = &_rtm;
  clib_memset (rtm, 0, sizeof (rwlock_test_main_t));

  while (unformat_check_input (i) != UNFORMAT_END_OF_INPUT)
    {
      if (0 == unformat (i, "threads/core %d", &rtm->threads_per_core)
	  && 0 == unformat (i, "cpu_mask_read %x", &rtm->cpu_mask_read)
	  && 0 == unformat (i, "cpu_mask_write %x", &rtm->cpu_mask_write)
	  && 0 == unformat (i, "increment %d", &rtm->increment_per_thread)
	  && 0 == unformat (i, "iterations %d", &rtm->iterations))
	{
	  clib_unix_warning ("unknown input '%U'", format_unformat_error, i);
	  return 1;
	}
    }

  rtm->read_cores = num_cores_in_cpu_mask (rtm->cpu_mask_read);
  rtm->write_cores = num_cores_in_cpu_mask (rtm->cpu_mask_write);

  uword total_increment = rtm->threads_per_core * rtm->write_cores *
    rtm->increment_per_thread;

  clib_rwlock_init (&rtm->rwlock);

  f64 average_time = 0;
  for (uword trial = 0; trial < rtm->iterations; trial++)
    {
      rtm->shared_count = 0;
      f64 elapse_time = 0;
      if (test_rwlock (rtm, &elapse_time) != total_increment)
	{
	  clib_rwlock_free (&rtm->rwlock);
	  fformat (stdout, "FAILED: expected count: %d, actual count: %d\n",
		   total_increment, rtm->shared_count);
	  return 1;
	}
      fformat (stdout, "Trial %d SUCCESS: %d = %d\n",
	       trial, rtm->shared_count, total_increment);
      average_time = (average_time * trial + elapse_time) / (trial + 1);
      fformat (stdout, "Average lock/unlock cycles: %.4e\n", average_time);
    }
  clib_rwlock_free (&rtm->rwlock);
  return 0;
}

#ifdef CLIB_UNIX
/** Launches a number of writer threads to simultaneously increment a global
    counter and a number of reader threads to continuously poll the counter,
    and records timestamps for rwlock performance benchmarking

    @param "threads/core [# threads/core]" - number of threads per core
    @param "cpu_mask_read [cpu_mask]" - reader thread cpu string e.g. input
            ff sets cpus 0 - 7
    @param "cpu_mask_write [cpu_mask]" - writer thread cpu string
    @param "increment [# increments]" - number of increments per writer thread
    @param "iterations [# iterations]" - number of iterations
    @returns exit code
*/
int
main (int argc, char *argv[])
{
  unformat_input_t i;
  i32 ret;
  clib_time_t time;

  clib_mem_init (0, 3ULL << 30);
  clib_time_init (&time);

  unformat_init_command_line (&i, argv);
  ret = test_rwlock_main (&i);
  unformat_free (&i);

  return ret;
}
#endif /* CLIB_UNIX */

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