qemu/tests/test-rcu-list.c
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   1/*
   2 * rcuq_test.c
   3 *
   4 * usage: rcuq_test <readers> <duration>
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19 *
  20 * Copyright (c) 2013 Mike D. Day, IBM Corporation.
  21 */
  22
  23#include "qemu/osdep.h"
  24#include "qemu/atomic.h"
  25#include "qemu/rcu.h"
  26#include "qemu/thread.h"
  27#include "qemu/rcu_queue.h"
  28
  29/*
  30 * Test variables.
  31 */
  32
  33static QemuMutex counts_mutex;
  34static long long n_reads = 0LL;
  35static long long n_updates = 0LL;
  36static int64_t n_reclaims;
  37static int64_t n_nodes_removed;
  38static long long n_nodes = 0LL;
  39static int g_test_in_charge = 0;
  40
  41static int nthreadsrunning;
  42
  43#define GOFLAG_INIT 0
  44#define GOFLAG_RUN  1
  45#define GOFLAG_STOP 2
  46
  47static int goflag = GOFLAG_INIT;
  48
  49#define RCU_READ_RUN 1000
  50#define RCU_UPDATE_RUN 10
  51#define NR_THREADS 100
  52#define RCU_Q_LEN 100
  53
  54static QemuThread threads[NR_THREADS];
  55static struct rcu_reader_data *data[NR_THREADS];
  56static int n_threads;
  57
  58static int select_random_el(int max)
  59{
  60    return (rand() % max);
  61}
  62
  63
  64static void create_thread(void *(*func)(void *))
  65{
  66    if (n_threads >= NR_THREADS) {
  67        fprintf(stderr, "Thread limit of %d exceeded!\n", NR_THREADS);
  68        exit(-1);
  69    }
  70    qemu_thread_create(&threads[n_threads], "test", func, &data[n_threads],
  71                       QEMU_THREAD_JOINABLE);
  72    n_threads++;
  73}
  74
  75static void wait_all_threads(void)
  76{
  77    int i;
  78
  79    for (i = 0; i < n_threads; i++) {
  80        qemu_thread_join(&threads[i]);
  81    }
  82    n_threads = 0;
  83}
  84
  85#ifndef TEST_LIST_TYPE
  86#define TEST_LIST_TYPE 1
  87#endif
  88
  89struct list_element {
  90#if TEST_LIST_TYPE == 1
  91    QLIST_ENTRY(list_element) entry;
  92#elif TEST_LIST_TYPE == 2
  93    QSIMPLEQ_ENTRY(list_element) entry;
  94#elif TEST_LIST_TYPE == 3
  95    QTAILQ_ENTRY(list_element) entry;
  96#elif TEST_LIST_TYPE == 4
  97    QSLIST_ENTRY(list_element) entry;
  98#else
  99#error Invalid TEST_LIST_TYPE
 100#endif
 101    struct rcu_head rcu;
 102};
 103
 104static void reclaim_list_el(struct rcu_head *prcu)
 105{
 106    struct list_element *el = container_of(prcu, struct list_element, rcu);
 107    g_free(el);
 108    /* Accessed only from call_rcu thread.  */
 109    atomic_set_i64(&n_reclaims, n_reclaims + 1);
 110}
 111
 112#if TEST_LIST_TYPE == 1
 113static QLIST_HEAD(, list_element) Q_list_head;
 114
 115#define TEST_NAME "qlist"
 116#define TEST_LIST_REMOVE_RCU        QLIST_REMOVE_RCU
 117#define TEST_LIST_INSERT_AFTER_RCU  QLIST_INSERT_AFTER_RCU
 118#define TEST_LIST_INSERT_HEAD_RCU   QLIST_INSERT_HEAD_RCU
 119#define TEST_LIST_FOREACH_RCU       QLIST_FOREACH_RCU
 120#define TEST_LIST_FOREACH_SAFE_RCU  QLIST_FOREACH_SAFE_RCU
 121
 122#elif TEST_LIST_TYPE == 2
 123static QSIMPLEQ_HEAD(, list_element) Q_list_head =
 124    QSIMPLEQ_HEAD_INITIALIZER(Q_list_head);
 125
 126#define TEST_NAME "qsimpleq"
 127#define TEST_LIST_REMOVE_RCU(el, f)                             \
 128         QSIMPLEQ_REMOVE_RCU(&Q_list_head, el, list_element, f)
 129
 130#define TEST_LIST_INSERT_AFTER_RCU(list_el, el, f)               \
 131         QSIMPLEQ_INSERT_AFTER_RCU(&Q_list_head, list_el, el, f)
 132
 133#define TEST_LIST_INSERT_HEAD_RCU   QSIMPLEQ_INSERT_HEAD_RCU
 134#define TEST_LIST_FOREACH_RCU       QSIMPLEQ_FOREACH_RCU
 135#define TEST_LIST_FOREACH_SAFE_RCU  QSIMPLEQ_FOREACH_SAFE_RCU
 136
 137#elif TEST_LIST_TYPE == 3
 138static QTAILQ_HEAD(, list_element) Q_list_head;
 139
 140#define TEST_NAME "qtailq"
 141#define TEST_LIST_REMOVE_RCU(el, f) QTAILQ_REMOVE_RCU(&Q_list_head, el, f)
 142
 143#define TEST_LIST_INSERT_AFTER_RCU(list_el, el, f)               \
 144           QTAILQ_INSERT_AFTER_RCU(&Q_list_head, list_el, el, f)
 145
 146#define TEST_LIST_INSERT_HEAD_RCU   QTAILQ_INSERT_HEAD_RCU
 147#define TEST_LIST_FOREACH_RCU       QTAILQ_FOREACH_RCU
 148#define TEST_LIST_FOREACH_SAFE_RCU  QTAILQ_FOREACH_SAFE_RCU
 149
 150#elif TEST_LIST_TYPE == 4
 151static QSLIST_HEAD(, list_element) Q_list_head;
 152
 153#define TEST_NAME "qslist"
 154#define TEST_LIST_REMOVE_RCU(el, f)                              \
 155         QSLIST_REMOVE_RCU(&Q_list_head, el, list_element, f)
 156
 157#define TEST_LIST_INSERT_AFTER_RCU(list_el, el, f)               \
 158         QSLIST_INSERT_AFTER_RCU(&Q_list_head, list_el, el, f)
 159
 160#define TEST_LIST_INSERT_HEAD_RCU   QSLIST_INSERT_HEAD_RCU
 161#define TEST_LIST_FOREACH_RCU       QSLIST_FOREACH_RCU
 162#define TEST_LIST_FOREACH_SAFE_RCU  QSLIST_FOREACH_SAFE_RCU
 163#else
 164#error Invalid TEST_LIST_TYPE
 165#endif
 166
 167static void *rcu_q_reader(void *arg)
 168{
 169    long long n_reads_local = 0;
 170    struct list_element *el;
 171
 172    rcu_register_thread();
 173
 174    *(struct rcu_reader_data **)arg = &rcu_reader;
 175    atomic_inc(&nthreadsrunning);
 176    while (atomic_read(&goflag) == GOFLAG_INIT) {
 177        g_usleep(1000);
 178    }
 179
 180    while (atomic_read(&goflag) == GOFLAG_RUN) {
 181        rcu_read_lock();
 182        TEST_LIST_FOREACH_RCU(el, &Q_list_head, entry) {
 183            n_reads_local++;
 184            if (atomic_read(&goflag) == GOFLAG_STOP) {
 185                break;
 186            }
 187        }
 188        rcu_read_unlock();
 189
 190        g_usleep(100);
 191    }
 192    qemu_mutex_lock(&counts_mutex);
 193    n_reads += n_reads_local;
 194    qemu_mutex_unlock(&counts_mutex);
 195
 196    rcu_unregister_thread();
 197    return NULL;
 198}
 199
 200
 201static void *rcu_q_updater(void *arg)
 202{
 203    int j, target_el;
 204    long long n_nodes_local = 0;
 205    long long n_updates_local = 0;
 206    long long n_removed_local = 0;
 207    struct list_element *el, *prev_el;
 208
 209    *(struct rcu_reader_data **)arg = &rcu_reader;
 210    atomic_inc(&nthreadsrunning);
 211    while (atomic_read(&goflag) == GOFLAG_INIT) {
 212        g_usleep(1000);
 213    }
 214
 215    while (atomic_read(&goflag) == GOFLAG_RUN) {
 216        target_el = select_random_el(RCU_Q_LEN);
 217        j = 0;
 218        /* FOREACH_RCU could work here but let's use both macros */
 219        TEST_LIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) {
 220            j++;
 221            if (target_el == j) {
 222                TEST_LIST_REMOVE_RCU(prev_el, entry);
 223                /* may be more than one updater in the future */
 224                call_rcu1(&prev_el->rcu, reclaim_list_el);
 225                n_removed_local++;
 226                break;
 227            }
 228        }
 229        if (atomic_read(&goflag) == GOFLAG_STOP) {
 230            break;
 231        }
 232        target_el = select_random_el(RCU_Q_LEN);
 233        j = 0;
 234        TEST_LIST_FOREACH_RCU(el, &Q_list_head, entry) {
 235            j++;
 236            if (target_el == j) {
 237                struct list_element *new_el = g_new(struct list_element, 1);
 238                n_nodes_local++;
 239                TEST_LIST_INSERT_AFTER_RCU(el, new_el, entry);
 240                break;
 241            }
 242        }
 243
 244        n_updates_local += 2;
 245        synchronize_rcu();
 246    }
 247    synchronize_rcu();
 248    qemu_mutex_lock(&counts_mutex);
 249    n_nodes += n_nodes_local;
 250    n_updates += n_updates_local;
 251    atomic_set_i64(&n_nodes_removed, n_nodes_removed + n_removed_local);
 252    qemu_mutex_unlock(&counts_mutex);
 253    return NULL;
 254}
 255
 256static void rcu_qtest_init(void)
 257{
 258    struct list_element *new_el;
 259    int i;
 260    nthreadsrunning = 0;
 261    srand(time(0));
 262    for (i = 0; i < RCU_Q_LEN; i++) {
 263        new_el = g_new(struct list_element, 1);
 264        TEST_LIST_INSERT_HEAD_RCU(&Q_list_head, new_el, entry);
 265    }
 266    qemu_mutex_lock(&counts_mutex);
 267    n_nodes += RCU_Q_LEN;
 268    qemu_mutex_unlock(&counts_mutex);
 269}
 270
 271static void rcu_qtest_run(int duration, int nreaders)
 272{
 273    int nthreads = nreaders + 1;
 274    while (atomic_read(&nthreadsrunning) < nthreads) {
 275        g_usleep(1000);
 276    }
 277
 278    atomic_set(&goflag, GOFLAG_RUN);
 279    sleep(duration);
 280    atomic_set(&goflag, GOFLAG_STOP);
 281    wait_all_threads();
 282}
 283
 284
 285static void rcu_qtest(const char *test, int duration, int nreaders)
 286{
 287    int i;
 288    long long n_removed_local = 0;
 289
 290    struct list_element *el, *prev_el;
 291
 292    rcu_qtest_init();
 293    for (i = 0; i < nreaders; i++) {
 294        create_thread(rcu_q_reader);
 295    }
 296    create_thread(rcu_q_updater);
 297    rcu_qtest_run(duration, nreaders);
 298
 299    TEST_LIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) {
 300        TEST_LIST_REMOVE_RCU(prev_el, entry);
 301        call_rcu1(&prev_el->rcu, reclaim_list_el);
 302        n_removed_local++;
 303    }
 304    qemu_mutex_lock(&counts_mutex);
 305    atomic_set_i64(&n_nodes_removed, n_nodes_removed + n_removed_local);
 306    qemu_mutex_unlock(&counts_mutex);
 307    synchronize_rcu();
 308    while (atomic_read_i64(&n_nodes_removed) > atomic_read_i64(&n_reclaims)) {
 309        g_usleep(100);
 310        synchronize_rcu();
 311    }
 312    if (g_test_in_charge) {
 313        g_assert_cmpint(atomic_read_i64(&n_nodes_removed), ==,
 314                        atomic_read_i64(&n_reclaims));
 315    } else {
 316        printf("%s: %d readers; 1 updater; nodes read: "  \
 317               "%lld, nodes removed: %"PRIi64"; nodes reclaimed: %"PRIi64"\n",
 318               test, nthreadsrunning - 1, n_reads,
 319               atomic_read_i64(&n_nodes_removed), atomic_read_i64(&n_reclaims));
 320        exit(0);
 321    }
 322}
 323
 324static void usage(int argc, char *argv[])
 325{
 326    fprintf(stderr, "Usage: %s duration nreaders\n", argv[0]);
 327    exit(-1);
 328}
 329
 330static int gtest_seconds;
 331
 332static void gtest_rcuq_one(void)
 333{
 334    rcu_qtest("rcuqtest", gtest_seconds / 4, 1);
 335}
 336
 337static void gtest_rcuq_few(void)
 338{
 339    rcu_qtest("rcuqtest", gtest_seconds / 4, 5);
 340}
 341
 342static void gtest_rcuq_many(void)
 343{
 344    rcu_qtest("rcuqtest", gtest_seconds / 2, 20);
 345}
 346
 347
 348int main(int argc, char *argv[])
 349{
 350    int duration = 0, readers = 0;
 351
 352    qemu_mutex_init(&counts_mutex);
 353    if (argc >= 2) {
 354        if (argv[1][0] == '-') {
 355            g_test_init(&argc, &argv, NULL);
 356            if (g_test_quick()) {
 357                gtest_seconds = 4;
 358            } else {
 359                gtest_seconds = 20;
 360            }
 361            g_test_add_func("/rcu/"TEST_NAME"/single-threaded", gtest_rcuq_one);
 362            g_test_add_func("/rcu/"TEST_NAME"/short-few", gtest_rcuq_few);
 363            g_test_add_func("/rcu/"TEST_NAME"/long-many", gtest_rcuq_many);
 364            g_test_in_charge = 1;
 365            return g_test_run();
 366        }
 367        duration = strtoul(argv[1], NULL, 0);
 368    }
 369    if (argc >= 3) {
 370        readers = strtoul(argv[2], NULL, 0);
 371    }
 372    if (duration && readers) {
 373        rcu_qtest(argv[0], duration, readers);
 374        return 0;
 375    }
 376
 377    usage(argc, argv);
 378    return -1;
 379}
 380