tools/virtio/ringtest/main.c

   1 /*
   2  * Copyright (C) 2016 Red Hat, Inc.
   3  * Author: Michael S. Tsirkin <mst@redhat.com>
   4  * This work is licensed under the terms of the GNU GPL, version 2.
   5  *
   6  * Command line processing and common functions for ring benchmarking.
   7  */
   8 #define _GNU_SOURCE
   9 #include <getopt.h>
  10 #include <pthread.h>
  11 #include <assert.h>
  12 #include <sched.h>
  13 #include "main.h"
  14 #include <sys/eventfd.h>
  15 #include <stdlib.h>
  16 #include <stdio.h>
  17 #include <unistd.h>
  18 #include <limits.h>
  19
  20 int runcycles = 10000000;
  21 int max_outstanding = INT_MAX;
  22 int batch = 1;
  23
  24 bool do_sleep = false;
  25 bool do_relax = false;
  26 bool do_exit = true;
  27
  28 unsigned ring_size = 256;
  29
  30 static int kickfd = -1;
  31 static int callfd = -1;
  32
  33 void notify(int fd)
  34 {
  35         unsigned long long v = 1;
  36         int r;
  37
  38         vmexit();
  39         r = write(fd, &v, sizeof v);
  40         assert(r == sizeof v);
  41         vmentry();
  42 }
  43
  44 void wait_for_notify(int fd)
  45 {
  46         unsigned long long v = 1;
  47         int r;
  48
  49         vmexit();
  50         r = read(fd, &v, sizeof v);
  51         assert(r == sizeof v);
  52         vmentry();
  53 }
  54
  55 void kick(void)
  56 {
  57         notify(kickfd);
  58 }
  59
  60 void wait_for_kick(void)
  61 {
  62         wait_for_notify(kickfd);
  63 }
  64
  65 void call(void)
  66 {
  67         notify(callfd);
  68 }
  69
  70 void wait_for_call(void)
  71 {
  72         wait_for_notify(callfd);
  73 }
  74
  75 void set_affinity(const char *arg)
  76 {
  77         cpu_set_t cpuset;
  78         int ret;
  79         pthread_t self;
  80         long int cpu;
  81         char *endptr;
  82
  83         if (!arg)
  84                 return;
  85
  86         cpu = strtol(arg, &endptr, 0);
  87         assert(!*endptr);
  88
  89         assert(cpu >= 0 || cpu < CPU_SETSIZE);
  90
  91         self = pthread_self();
  92         CPU_ZERO(&cpuset);
  93         CPU_SET(cpu, &cpuset);
  94
  95         ret = pthread_setaffinity_np(self, sizeof(cpu_set_t), &cpuset);
  96         assert(!ret);
  97 }
  98
  99 static void run_guest(void)
 100 {
 101         int completed_before;
 102         int completed = 0;
 103         int started = 0;
 104         int bufs = runcycles;
 105         int spurious = 0;
 106         int r;
 107         unsigned len;
 108         void *buf;
 109         int tokick = batch;
 110
 111         for (;;) {
 112                 if (do_sleep)
 113                         disable_call();
 114                 completed_before = completed;
 115                 do {
 116                         if (started < bufs &&
 117                             started - completed < max_outstanding) {
 118                                 r = add_inbuf(0, "Buffer\n", "Hello, world!");
 119                                 if (__builtin_expect(r == 0, true)) {
 120                                         ++started;
 121                                         if (!--tokick) {
 122                                                 tokick = batch;
 123                                                 if (do_sleep)
 124                                                         kick_available();
 125                                         }
 126
 127                                 }
 128                         } else
 129                                 r = -1;
 130
 131                         /* Flush out completed bufs if any */
 132                         if (get_buf(&len, &buf)) {
 133                                 ++completed;
 134                                 if (__builtin_expect(completed == bufs, false))
 135                                         return;
 136                                 r = 0;
 137                         }
 138                 } while (r == 0);
 139                 if (completed == completed_before)
 140                         ++spurious;
 141                 assert(completed <= bufs);
 142                 assert(started <= bufs);
 143                 if (do_sleep) {
 144                         if (enable_call())
 145                                 wait_for_call();
 146                 } else {
 147                         poll_used();
 148                 }
 149         }
 150 }
 151
 152 static void run_host(void)
 153 {
 154         int completed_before;
 155         int completed = 0;
 156         int spurious = 0;
 157         int bufs = runcycles;
 158         unsigned len;
 159         void *buf;
 160
 161         for (;;) {
 162                 if (do_sleep) {
 163                         if (enable_kick())
 164                                 wait_for_kick();
 165                 } else {
 166                         poll_avail();
 167                 }
 168                 if (do_sleep)
 169                         disable_kick();
 170                 completed_before = completed;
 171                 while (__builtin_expect(use_buf(&len, &buf), true)) {
 172                         if (do_sleep)
 173                                 call_used();
 174                         ++completed;
 175                         if (__builtin_expect(completed == bufs, false))
 176                                 return;
 177                 }
 178                 if (completed == completed_before)
 179                         ++spurious;
 180                 assert(completed <= bufs);
 181                 if (completed == bufs)
 182                         break;
 183         }
 184 }
 185
 186 void *start_guest(void *arg)
 187 {
 188         set_affinity(arg);
 189         run_guest();
 190         pthread_exit(NULL);
 191 }
 192
 193 void *start_host(void *arg)
 194 {
 195         set_affinity(arg);
 196         run_host();
 197         pthread_exit(NULL);
 198 }
 199
 200 static const char optstring[] = "";
 201 static const struct option longopts[] = {
 202         {
 203                 .name = "help",
 204                 .has_arg = no_argument,
 205                 .val = 'h',
 206         },
 207         {
 208                 .name = "host-affinity",
 209                 .has_arg = required_argument,
 210                 .val = 'H',
 211         },
 212         {
 213                 .name = "guest-affinity",
 214                 .has_arg = required_argument,
 215                 .val = 'G',
 216         },
 217         {
 218                 .name = "ring-size",
 219                 .has_arg = required_argument,
 220                 .val = 'R',
 221         },
 222         {
 223                 .name = "run-cycles",
 224                 .has_arg = required_argument,
 225                 .val = 'C',
 226         },
 227         {
 228                 .name = "outstanding",
 229                 .has_arg = required_argument,
 230                 .val = 'o',
 231         },
 232         {
 233                 .name = "batch",
 234                 .has_arg = required_argument,
 235                 .val = 'b',
 236         },
 237         {
 238                 .name = "sleep",
 239                 .has_arg = no_argument,
 240                 .val = 's',
 241         },
 242         {
 243                 .name = "relax",
 244                 .has_arg = no_argument,
 245                 .val = 'x',
 246         },
 247         {
 248                 .name = "exit",
 249                 .has_arg = no_argument,
 250                 .val = 'e',
 251         },
 252         {
 253         }
 254 };
 255
 256 static void help(void)
 257 {
 258         fprintf(stderr, "Usage: <test> [--help]"
 259                 " [--host-affinity H]"
 260                 " [--guest-affinity G]"
 261                 " [--ring-size R (default: %d)]"
 262                 " [--run-cycles C (default: %d)]"
 263                 " [--batch b]"
 264                 " [--outstanding o]"
 265                 " [--sleep]"
 266                 " [--relax]"
 267                 " [--exit]"
 268                 "\n",
 269                 ring_size,
 270                 runcycles);
 271 }
 272
 273 int main(int argc, char **argv)
 274 {
 275         int ret;
 276         pthread_t host, guest;
 277         void *tret;
 278         char *host_arg = NULL;
 279         char *guest_arg = NULL;
 280         char *endptr;
 281         long int c;
 282
 283         kickfd = eventfd(0, 0);
 284         assert(kickfd >= 0);
 285         callfd = eventfd(0, 0);
 286         assert(callfd >= 0);
 287
 288         for (;;) {
 289                 int o = getopt_long(argc, argv, optstring, longopts, NULL);
 290                 switch (o) {
 291                 case -1:
 292                         goto done;
 293                 case '?':
 294                         help();
 295                         exit(2);
 296                 case 'H':
 297                         host_arg = optarg;
 298                         break;
 299                 case 'G':
 300                         guest_arg = optarg;
 301                         break;
 302                 case 'R':
 303                         ring_size = strtol(optarg, &endptr, 0);
 304                         assert(ring_size && !(ring_size & (ring_size - 1)));
 305                         assert(!*endptr);
 306                         break;
 307                 case 'C':
 308                         c = strtol(optarg, &endptr, 0);
 309                         assert(!*endptr);
 310                         assert(c > 0 && c < INT_MAX);
 311                         runcycles = c;
 312                         break;
 313                 case 'o':
 314                         c = strtol(optarg, &endptr, 0);
 315                         assert(!*endptr);
 316                         assert(c > 0 && c < INT_MAX);
 317                         max_outstanding = c;
 318                         break;
 319                 case 'b':
 320                         c = strtol(optarg, &endptr, 0);
 321                         assert(!*endptr);
 322                         assert(c > 0 && c < INT_MAX);
 323                         batch = c;
 324                         break;
 325                 case 's':
 326                         do_sleep = true;
 327                         break;
 328                 case 'x':
 329                         do_relax = true;
 330                         break;
 331                 case 'e':
 332                         do_exit = true;
 333                         break;
 334                 default:
 335                         help();
 336                         exit(4);
 337                         break;
 338                 }
 339         }
 340
 341         /* does nothing here, used to make sure all smp APIs compile */
 342         smp_acquire();
 343         smp_release();
 344         smp_mb();
 345 done:
 346
 347         if (batch > max_outstanding)
 348                 batch = max_outstanding;
 349
 350         if (optind < argc) {
 351                 help();
 352                 exit(4);
 353         }
 354         alloc_ring();
 355
 356         ret = pthread_create(&host, NULL, start_host, host_arg);
 357         assert(!ret);
 358         ret = pthread_create(&guest, NULL, start_guest, guest_arg);
 359         assert(!ret);
 360
 361         ret = pthread_join(guest, &tret);
 362         assert(!ret);
 363         ret = pthread_join(host, &tret);
 364         assert(!ret);
 365         return 0;
 366 }