tests/qht-bench.c

   1 /*
   2  * Copyright (C) 2016, Emilio G. Cota <cota@braap.org>
   3  *
   4  * License: GNU GPL, version 2 or later.
   5  *   See the COPYING file in the top-level directory.
   6  */
   7 #include "qemu/osdep.h"
   8 #include "qemu/processor.h"
   9 #include "qemu/atomic.h"
  10 #include "qemu/qht.h"
  11 #include "qemu/rcu.h"
  12 #include "exec/tb-hash-xx.h"
  13
  14 struct thread_stats {
  15     size_t rd;
  16     size_t not_rd;
  17     size_t in;
  18     size_t not_in;
  19     size_t rm;
  20     size_t not_rm;
  21     size_t rz;
  22     size_t not_rz;
  23 };
  24
  25 struct thread_info {
  26     void (*func)(struct thread_info *);
  27     struct thread_stats stats;
  28     uint64_t r;
  29     bool write_op; /* writes alternate between insertions and removals */
  30     bool resize_down;
  31 } QEMU_ALIGNED(64); /* avoid false sharing among threads */
  32
  33 static struct qht ht;
  34 static QemuThread *rw_threads;
  35
  36 #define DEFAULT_RANGE (4096)
  37 #define DEFAULT_QHT_N_ELEMS DEFAULT_RANGE
  38
  39 static unsigned int duration = 1;
  40 static unsigned int n_rw_threads = 1;
  41 static unsigned long lookup_range = DEFAULT_RANGE;
  42 static unsigned long update_range = DEFAULT_RANGE;
  43 static size_t init_range = DEFAULT_RANGE;
  44 static size_t init_size = DEFAULT_RANGE;
  45 static size_t n_ready_threads;
  46 static long populate_offset;
  47 static long *keys;
  48
  49 static size_t resize_min;
  50 static size_t resize_max;
  51 static struct thread_info *rz_info;
  52 static unsigned long resize_delay = 1000;
  53 static double resize_rate; /* 0.0 to 1.0 */
  54 static unsigned int n_rz_threads = 1;
  55 static QemuThread *rz_threads;
  56
  57 static double update_rate; /* 0.0 to 1.0 */
  58 static uint64_t update_threshold;
  59 static uint64_t resize_threshold;
  60
  61 static size_t qht_n_elems = DEFAULT_QHT_N_ELEMS;
  62 static int qht_mode;
  63
  64 static bool test_start;
  65 static bool test_stop;
  66
  67 static struct thread_info *rw_info;
  68
  69 static const char commands_string[] =
  70     " -d = duration, in seconds\n"
  71     " -n = number of threads\n"
  72     "\n"
  73     " -o = offset at which keys start\n"
  74     "\n"
  75     " -g = set -s,-k,-K,-l,-r to the same value\n"
  76     " -s = initial size hint\n"
  77     " -k = initial number of keys\n"
  78     " -K = initial range of keys (will be rounded up to pow2)\n"
  79     " -l = lookup range of keys (will be rounded up to pow2)\n"
  80     " -r = update range of keys (will be rounded up to pow2)\n"
  81     "\n"
  82     " -u = update rate (0.0 to 100.0), 50/50 split of insertions/removals\n"
  83     "\n"
  84     " -R = enable auto-resize\n"
  85     " -S = resize rate (0.0 to 100.0)\n"
  86     " -D = delay (in us) between potential resizes\n"
  87     " -N = number of resize threads";
  88
  89 static void usage_complete(int argc, char *argv[])
  90 {
  91     fprintf(stderr, "Usage: %s [options]\n", argv[0]);
  92     fprintf(stderr, "options:\n%s\n", commands_string);
  93     exit(-1);
  94 }
  95
  96 static bool is_equal(const void *obj, const void *userp)
  97 {
  98     const long *a = obj;
  99     const long *b = userp;
 100
 101     return *a == *b;
 102 }
 103
 104 static inline uint32_t h(unsigned long v)
 105 {
 106     return tb_hash_func6(v, 0, 0, 0);
 107 }
 108
 109 /*
 110  * From: https://en.wikipedia.org/wiki/Xorshift
 111  * This is faster than rand_r(), and gives us a wider range (RAND_MAX is only
 112  * guaranteed to be >= INT_MAX).
 113  */
 114 static uint64_t xorshift64star(uint64_t x)
 115 {
 116     x ^= x >> 12; /* a */
 117     x ^= x << 25; /* b */
 118     x ^= x >> 27; /* c */
 119     return x * UINT64_C(2685821657736338717);
 120 }
 121
 122 static void do_rz(struct thread_info *info)
 123 {
 124     struct thread_stats *stats = &info->stats;
 125
 126     if (info->r < resize_threshold) {
 127         size_t size = info->resize_down ? resize_min : resize_max;
 128         bool resized;
 129
 130         resized = qht_resize(&ht, size);
 131         info->resize_down = !info->resize_down;
 132
 133         if (resized) {
 134             stats->rz++;
 135         } else {
 136             stats->not_rz++;
 137         }
 138     }
 139     g_usleep(resize_delay);
 140 }
 141
 142 static void do_rw(struct thread_info *info)
 143 {
 144     struct thread_stats *stats = &info->stats;
 145     uint32_t hash;
 146     long *p;
 147
 148     if (info->r >= update_threshold) {
 149         bool read;
 150
 151         p = &keys[info->r & (lookup_range - 1)];
 152         hash = h(*p);
 153         read = qht_lookup(&ht, is_equal, p, hash);
 154         if (read) {
 155             stats->rd++;
 156         } else {
 157             stats->not_rd++;
 158         }
 159     } else {
 160         p = &keys[info->r & (update_range - 1)];
 161         hash = h(*p);
 162         if (info->write_op) {
 163             bool written = false;
 164
 165             if (qht_lookup(&ht, is_equal, p, hash) == NULL) {
 166                 written = qht_insert(&ht, p, hash);
 167             }
 168             if (written) {
 169                 stats->in++;
 170             } else {
 171                 stats->not_in++;
 172             }
 173         } else {
 174             bool removed = false;
 175
 176             if (qht_lookup(&ht, is_equal, p, hash)) {
 177                 removed = qht_remove(&ht, p, hash);
 178             }
 179             if (removed) {
 180                 stats->rm++;
 181             } else {
 182                 stats->not_rm++;
 183             }
 184         }
 185         info->write_op = !info->write_op;
 186     }
 187 }
 188
 189 static void *thread_func(void *p)
 190 {
 191     struct thread_info *info = p;
 192
 193     rcu_register_thread();
 194
 195     atomic_inc(&n_ready_threads);
 196     while (!atomic_read(&test_start)) {
 197         cpu_relax();
 198     }
 199
 200     rcu_read_lock();
 201     while (!atomic_read(&test_stop)) {
 202         info->r = xorshift64star(info->r);
 203         info->func(info);
 204     }
 205     rcu_read_unlock();
 206
 207     rcu_unregister_thread();
 208     return NULL;
 209 }
 210
 211 /* sets everything except info->func */
 212 static void prepare_thread_info(struct thread_info *info, int i)
 213 {
 214     /* seed for the RNG; each thread should have a different one */
 215     info->r = (i + 1) ^ time(NULL);
 216     /* the first update will be a write */
 217     info->write_op = true;
 218     /* the first resize will be down */
 219     info->resize_down = true;
 220
 221     memset(&info->stats, 0, sizeof(info->stats));
 222 }
 223
 224 static void
 225 th_create_n(QemuThread **threads, struct thread_info **infos, const char *name,
 226             void (*func)(struct thread_info *), int offset, int n)
 227 {
 228     struct thread_info *info;
 229     QemuThread *th;
 230     int i;
 231
 232     th = g_malloc(sizeof(*th) * n);
 233     *threads = th;
 234
 235     info = qemu_memalign(64, sizeof(*info) * n);
 236     *infos = info;
 237
 238     for (i = 0; i < n; i++) {
 239         prepare_thread_info(&info[i], offset + i);
 240         info[i].func = func;
 241         qemu_thread_create(&th[i], name, thread_func, &info[i],
 242                            QEMU_THREAD_JOINABLE);
 243     }
 244 }
 245
 246 static void create_threads(void)
 247 {
 248     th_create_n(&rw_threads, &rw_info, "rw", do_rw, 0, n_rw_threads);
 249     th_create_n(&rz_threads, &rz_info, "rz", do_rz, n_rw_threads, n_rz_threads);
 250 }
 251
 252 static void pr_params(void)
 253 {
 254     printf("Parameters:\n");
 255     printf(" duration:          %d s\n", duration);
 256     printf(" # of threads:      %u\n", n_rw_threads);
 257     printf(" initial # of keys: %zu\n", init_size);
 258     printf(" initial size hint: %zu\n", qht_n_elems);
 259     printf(" auto-resize:       %s\n",
 260            qht_mode & QHT_MODE_AUTO_RESIZE ? "on" : "off");
 261     if (resize_rate) {
 262         printf(" resize_rate:       %f%%\n", resize_rate * 100.0);
 263         printf(" resize range:      %zu-%zu\n", resize_min, resize_max);
 264         printf(" # resize threads   %u\n", n_rz_threads);
 265     }
 266     printf(" update rate:       %f%%\n", update_rate * 100.0);
 267     printf(" offset:            %ld\n", populate_offset);
 268     printf(" initial key range: %zu\n", init_range);
 269     printf(" lookup range:      %lu\n", lookup_range);
 270     printf(" update range:      %lu\n", update_range);
 271 }
 272
 273 static void do_threshold(double rate, uint64_t *threshold)
 274 {
 275     if (rate == 1.0) {
 276         *threshold = UINT64_MAX;
 277     } else {
 278         *threshold = rate * UINT64_MAX;
 279     }
 280 }
 281
 282 static void htable_init(void)
 283 {
 284     unsigned long n = MAX(init_range, update_range);
 285     uint64_t r = time(NULL);
 286     size_t retries = 0;
 287     size_t i;
 288
 289     /* avoid allocating memory later by allocating all the keys now */
 290     keys = g_malloc(sizeof(*keys) * n);
 291     for (i = 0; i < n; i++) {
 292         keys[i] = populate_offset + i;
 293     }
 294
 295     /* some sanity checks */
 296     g_assert_cmpuint(lookup_range, <=, n);
 297
 298     /* compute thresholds */
 299     do_threshold(update_rate, &update_threshold);
 300     do_threshold(resize_rate, &resize_threshold);
 301
 302     if (resize_rate) {
 303         resize_min = n / 2;
 304         resize_max = n;
 305         assert(resize_min < resize_max);
 306     } else {
 307         n_rz_threads = 0;
 308     }
 309
 310     /* initialize the hash table */
 311     qht_init(&ht, qht_n_elems, qht_mode);
 312     assert(init_size <= init_range);
 313
 314     pr_params();
 315
 316     fprintf(stderr, "Initialization: populating %zu items...", init_size);
 317     for (i = 0; i < init_size; i++) {
 318         for (;;) {
 319             uint32_t hash;
 320             long *p;
 321
 322             r = xorshift64star(r);
 323             p = &keys[r & (init_range - 1)];
 324             hash = h(*p);
 325             if (qht_insert(&ht, p, hash)) {
 326                 break;
 327             }
 328             retries++;
 329         }
 330     }
 331     fprintf(stderr, " populated after %zu retries\n", retries);
 332 }
 333
 334 static void add_stats(struct thread_stats *s, struct thread_info *info, int n)
 335 {
 336     int i;
 337
 338     for (i = 0; i < n; i++) {
 339         struct thread_stats *stats = &info[i].stats;
 340
 341         s->rd += stats->rd;
 342         s->not_rd += stats->not_rd;
 343
 344         s->in += stats->in;
 345         s->not_in += stats->not_in;
 346
 347         s->rm += stats->rm;
 348         s->not_rm += stats->not_rm;
 349
 350         s->rz += stats->rz;
 351         s->not_rz += stats->not_rz;
 352     }
 353 }
 354
 355 static void pr_stats(void)
 356 {
 357     struct thread_stats s = {};
 358     double tx;
 359
 360     add_stats(&s, rw_info, n_rw_threads);
 361     add_stats(&s, rz_info, n_rz_threads);
 362
 363     printf("Results:\n");
 364
 365     if (resize_rate) {
 366         printf(" Resizes:           %zu (%.2f%% of %zu)\n",
 367                s.rz, (double)s.rz / (s.rz + s.not_rz) * 100, s.rz + s.not_rz);
 368     }
 369
 370     printf(" Read:              %.2f M (%.2f%% of %.2fM)\n",
 371            (double)s.rd / 1e6,
 372            (double)s.rd / (s.rd + s.not_rd) * 100,
 373            (double)(s.rd + s.not_rd) / 1e6);
 374     printf(" Inserted:          %.2f M (%.2f%% of %.2fM)\n",
 375            (double)s.in / 1e6,
 376            (double)s.in / (s.in + s.not_in) * 100,
 377            (double)(s.in + s.not_in) / 1e6);
 378     printf(" Removed:           %.2f M (%.2f%% of %.2fM)\n",
 379            (double)s.rm / 1e6,
 380            (double)s.rm / (s.rm + s.not_rm) * 100,
 381            (double)(s.rm + s.not_rm) / 1e6);
 382
 383     tx = (s.rd + s.not_rd + s.in + s.not_in + s.rm + s.not_rm) / 1e6 / duration;
 384     printf(" Throughput:        %.2f MT/s\n", tx);
 385     printf(" Throughput/thread: %.2f MT/s/thread\n", tx / n_rw_threads);
 386 }
 387
 388 static void run_test(void)
 389 {
 390     unsigned int remaining;
 391     int i;
 392
 393     while (atomic_read(&n_ready_threads) != n_rw_threads + n_rz_threads) {
 394         cpu_relax();
 395     }
 396     atomic_set(&test_start, true);
 397     do {
 398         remaining = sleep(duration);
 399     } while (remaining);
 400     atomic_set(&test_stop, true);
 401
 402     for (i = 0; i < n_rw_threads; i++) {
 403         qemu_thread_join(&rw_threads[i]);
 404     }
 405     for (i = 0; i < n_rz_threads; i++) {
 406         qemu_thread_join(&rz_threads[i]);
 407     }
 408 }
 409
 410 static void parse_args(int argc, char *argv[])
 411 {
 412     int c;
 413
 414     for (;;) {
 415         c = getopt(argc, argv, "d:D:g:k:K:l:hn:N:o:r:Rs:S:u:");
 416         if (c < 0) {
 417             break;
 418         }
 419         switch (c) {
 420         case 'd':
 421             duration = atoi(optarg);
 422             break;
 423         case 'D':
 424             resize_delay = atol(optarg);
 425             break;
 426         case 'g':
 427             init_range = pow2ceil(atol(optarg));
 428             lookup_range = pow2ceil(atol(optarg));
 429             update_range = pow2ceil(atol(optarg));
 430             qht_n_elems = atol(optarg);
 431             init_size = atol(optarg);
 432             break;
 433         case 'h':
 434             usage_complete(argc, argv);
 435             exit(0);
 436         case 'k':
 437             init_size = atol(optarg);
 438             break;
 439         case 'K':
 440             init_range = pow2ceil(atol(optarg));
 441             break;
 442         case 'l':
 443             lookup_range = pow2ceil(atol(optarg));
 444             break;
 445         case 'n':
 446             n_rw_threads = atoi(optarg);
 447             break;
 448         case 'N':
 449             n_rz_threads = atoi(optarg);
 450             break;
 451         case 'o':
 452             populate_offset = atol(optarg);
 453             break;
 454         case 'r':
 455             update_range = pow2ceil(atol(optarg));
 456             break;
 457         case 'R':
 458             qht_mode |= QHT_MODE_AUTO_RESIZE;
 459             break;
 460         case 's':
 461             qht_n_elems = atol(optarg);
 462             break;
 463         case 'S':
 464             resize_rate = atof(optarg) / 100.0;
 465             if (resize_rate > 1.0) {
 466                 resize_rate = 1.0;
 467             }
 468             break;
 469         case 'u':
 470             update_rate = atof(optarg) / 100.0;
 471             if (update_rate > 1.0) {
 472                 update_rate = 1.0;
 473             }
 474             break;
 475         }
 476     }
 477 }
 478
 479 int main(int argc, char *argv[])
 480 {
 481     parse_args(argc, argv);
 482     htable_init();
 483     create_threads();
 484     run_test();
 485     pr_stats();
 486     return 0;
 487 }