tools/testing/selftests/net/tcp_mmap.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright 2018 Google Inc.
   4  * Author: Eric Dumazet (edumazet@google.com)
   5  *
   6  * Reference program demonstrating tcp mmap() usage,
   7  * and SO_RCVLOWAT hints for receiver.
   8  *
   9  * Note : NIC with header split is needed to use mmap() on TCP :
  10  * Each incoming frame must be a multiple of PAGE_SIZE bytes of TCP payload.
  11  *
  12  * How to use on loopback interface :
  13  *
  14  *  ifconfig lo mtu 61512  # 15*4096 + 40 (ipv6 header) + 32 (TCP with TS option header)
  15  *  tcp_mmap -s -z &
  16  *  tcp_mmap -H ::1 -z
  17  *
  18  *  Or leave default lo mtu, but use -M option to set TCP_MAXSEG option to (4096 + 12)
  19  *      (4096 : page size on x86, 12: TCP TS option length)
  20  *  tcp_mmap -s -z -M $((4096+12)) &
  21  *  tcp_mmap -H ::1 -z -M $((4096+12))
  22  *
  23  * Note: -z option on sender uses MSG_ZEROCOPY, which forces a copy when packets go through loopback interface.
  24  *       We might use sendfile() instead, but really this test program is about mmap(), for receivers ;)
  25  *
  26  * $ ./tcp_mmap -s &                                 # Without mmap()
  27  * $ for i in {1..4}; do ./tcp_mmap -H ::1 -z ; done
  28  * received 32768 MB (0 % mmap'ed) in 14.1157 s, 19.4732 Gbit
  29  *   cpu usage user:0.057 sys:7.815, 240.234 usec per MB, 65531 c-switches
  30  * received 32768 MB (0 % mmap'ed) in 14.6833 s, 18.7204 Gbit
  31  *  cpu usage user:0.043 sys:8.103, 248.596 usec per MB, 65524 c-switches
  32  * received 32768 MB (0 % mmap'ed) in 11.143 s, 24.6682 Gbit
  33  *   cpu usage user:0.044 sys:6.576, 202.026 usec per MB, 65519 c-switches
  34  * received 32768 MB (0 % mmap'ed) in 14.9056 s, 18.4413 Gbit
  35  *   cpu usage user:0.036 sys:8.193, 251.129 usec per MB, 65530 c-switches
  36  * $ kill %1   # kill tcp_mmap server
  37  *
  38  * $ ./tcp_mmap -s -z &                              # With mmap()
  39  * $ for i in {1..4}; do ./tcp_mmap -H ::1 -z ; done
  40  * received 32768 MB (99.9939 % mmap'ed) in 6.73792 s, 40.7956 Gbit
  41  *   cpu usage user:0.045 sys:2.827, 87.6465 usec per MB, 65532 c-switches
  42  * received 32768 MB (99.9939 % mmap'ed) in 7.26732 s, 37.8238 Gbit
  43  *   cpu usage user:0.037 sys:3.087, 95.3369 usec per MB, 65532 c-switches
  44  * received 32768 MB (99.9939 % mmap'ed) in 7.61661 s, 36.0893 Gbit
  45  *   cpu usage user:0.046 sys:3.559, 110.016 usec per MB, 65529 c-switches
  46  * received 32768 MB (99.9939 % mmap'ed) in 7.43764 s, 36.9577 Gbit
  47  *   cpu usage user:0.035 sys:3.467, 106.873 usec per MB, 65530 c-switches
  48  */
  49 #define _GNU_SOURCE
  50 #include <pthread.h>
  51 #include <sys/types.h>
  52 #include <fcntl.h>
  53 #include <error.h>
  54 #include <sys/socket.h>
  55 #include <sys/mman.h>
  56 #include <sys/resource.h>
  57 #include <unistd.h>
  58 #include <string.h>
  59 #include <stdlib.h>
  60 #include <stdio.h>
  61 #include <errno.h>
  62 #include <time.h>
  63 #include <sys/time.h>
  64 #include <netinet/in.h>
  65 #include <arpa/inet.h>
  66 #include <poll.h>
  67 #include <linux/tcp.h>
  68 #include <assert.h>
  69
  70 #ifndef MSG_ZEROCOPY
  71 #define MSG_ZEROCOPY    0x4000000
  72 #endif
  73
  74 #define FILE_SZ (1UL << 35)
  75 static int cfg_family = AF_INET6;
  76 static socklen_t cfg_alen = sizeof(struct sockaddr_in6);
  77 static int cfg_port = 8787;
  78
  79 static int rcvbuf; /* Default: autotuning.  Can be set with -r <integer> option */
  80 static int sndbuf; /* Default: autotuning.  Can be set with -w <integer> option */
  81 static int zflg; /* zero copy option. (MSG_ZEROCOPY for sender, mmap() for receiver */
  82 static int xflg; /* hash received data (simple xor) (-h option) */
  83 static int keepflag; /* -k option: receiver shall keep all received file in memory (no munmap() calls) */
  84
  85 static int chunk_size  = 512*1024;
  86
  87 unsigned long htotal;
  88
  89 static inline void prefetch(const void *x)
  90 {
  91 #if defined(__x86_64__)
  92         asm volatile("prefetcht0 %P0" : : "m" (*(const char *)x));
  93 #endif
  94 }
  95
  96 void hash_zone(void *zone, unsigned int length)
  97 {
  98         unsigned long temp = htotal;
  99
 100         while (length >= 8*sizeof(long)) {
 101                 prefetch(zone + 384);
 102                 temp ^= *(unsigned long *)zone;
 103                 temp ^= *(unsigned long *)(zone + sizeof(long));
 104                 temp ^= *(unsigned long *)(zone + 2*sizeof(long));
 105                 temp ^= *(unsigned long *)(zone + 3*sizeof(long));
 106                 temp ^= *(unsigned long *)(zone + 4*sizeof(long));
 107                 temp ^= *(unsigned long *)(zone + 5*sizeof(long));
 108                 temp ^= *(unsigned long *)(zone + 6*sizeof(long));
 109                 temp ^= *(unsigned long *)(zone + 7*sizeof(long));
 110                 zone += 8*sizeof(long);
 111                 length -= 8*sizeof(long);
 112         }
 113         while (length >= 1) {
 114                 temp ^= *(unsigned char *)zone;
 115                 zone += 1;
 116                 length--;
 117         }
 118         htotal = temp;
 119 }
 120
 121 void *child_thread(void *arg)
 122 {
 123         unsigned long total_mmap = 0, total = 0;
 124         struct tcp_zerocopy_receive zc;
 125         unsigned long delta_usec;
 126         int flags = MAP_SHARED;
 127         struct timeval t0, t1;
 128         char *buffer = NULL;
 129         void *addr = NULL;
 130         double throughput;
 131         struct rusage ru;
 132         int lu, fd;
 133
 134         fd = (int)(unsigned long)arg;
 135
 136         gettimeofday(&t0, NULL);
 137
 138         fcntl(fd, F_SETFL, O_NDELAY);
 139         buffer = malloc(chunk_size);
 140         if (!buffer) {
 141                 perror("malloc");
 142                 goto error;
 143         }
 144         if (zflg) {
 145                 addr = mmap(NULL, chunk_size, PROT_READ, flags, fd, 0);
 146                 if (addr == (void *)-1)
 147                         zflg = 0;
 148         }
 149         while (1) {
 150                 struct pollfd pfd = { .fd = fd, .events = POLLIN, };
 151                 int sub;
 152
 153                 poll(&pfd, 1, 10000);
 154                 if (zflg) {
 155                         socklen_t zc_len = sizeof(zc);
 156                         int res;
 157
 158                         zc.address = (__u64)addr;
 159                         zc.length = chunk_size;
 160                         zc.recv_skip_hint = 0;
 161                         res = getsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE,
 162                                          &zc, &zc_len);
 163                         if (res == -1)
 164                                 break;
 165
 166                         if (zc.length) {
 167                                 assert(zc.length <= chunk_size);
 168                                 total_mmap += zc.length;
 169                                 if (xflg)
 170                                         hash_zone(addr, zc.length);
 171                                 total += zc.length;
 172                         }
 173                         if (zc.recv_skip_hint) {
 174                                 assert(zc.recv_skip_hint <= chunk_size);
 175                                 lu = read(fd, buffer, zc.recv_skip_hint);
 176                                 if (lu > 0) {
 177                                         if (xflg)
 178                                                 hash_zone(buffer, lu);
 179                                         total += lu;
 180                                 }
 181                         }
 182                         continue;
 183                 }
 184                 sub = 0;
 185                 while (sub < chunk_size) {
 186                         lu = read(fd, buffer + sub, chunk_size - sub);
 187                         if (lu == 0)
 188                                 goto end;
 189                         if (lu < 0)
 190                                 break;
 191                         if (xflg)
 192                                 hash_zone(buffer + sub, lu);
 193                         total += lu;
 194                         sub += lu;
 195                 }
 196         }
 197 end:
 198         gettimeofday(&t1, NULL);
 199         delta_usec = (t1.tv_sec - t0.tv_sec) * 1000000 + t1.tv_usec - t0.tv_usec;
 200
 201         throughput = 0;
 202         if (delta_usec)
 203                 throughput = total * 8.0 / (double)delta_usec / 1000.0;
 204         getrusage(RUSAGE_THREAD, &ru);
 205         if (total > 1024*1024) {
 206                 unsigned long total_usec;
 207                 unsigned long mb = total >> 20;
 208                 total_usec = 1000000*ru.ru_utime.tv_sec + ru.ru_utime.tv_usec +
 209                              1000000*ru.ru_stime.tv_sec + ru.ru_stime.tv_usec;
 210                 printf("received %lg MB (%lg %% mmap'ed) in %lg s, %lg Gbit\n"
 211                        "  cpu usage user:%lg sys:%lg, %lg usec per MB, %lu c-switches\n",
 212                                 total / (1024.0 * 1024.0),
 213                                 100.0*total_mmap/total,
 214                                 (double)delta_usec / 1000000.0,
 215                                 throughput,
 216                                 (double)ru.ru_utime.tv_sec + (double)ru.ru_utime.tv_usec / 1000000.0,
 217                                 (double)ru.ru_stime.tv_sec + (double)ru.ru_stime.tv_usec / 1000000.0,
 218                                 (double)total_usec/mb,
 219                                 ru.ru_nvcsw);
 220         }
 221 error:
 222         free(buffer);
 223         close(fd);
 224         if (zflg)
 225                 munmap(addr, chunk_size);
 226         pthread_exit(0);
 227 }
 228
 229 static void apply_rcvsnd_buf(int fd)
 230 {
 231         if (rcvbuf && setsockopt(fd, SOL_SOCKET,
 232                                  SO_RCVBUF, &rcvbuf, sizeof(rcvbuf)) == -1) {
 233                 perror("setsockopt SO_RCVBUF");
 234         }
 235
 236         if (sndbuf && setsockopt(fd, SOL_SOCKET,
 237                                  SO_SNDBUF, &sndbuf, sizeof(sndbuf)) == -1) {
 238                 perror("setsockopt SO_SNDBUF");
 239         }
 240 }
 241
 242
 243 static void setup_sockaddr(int domain, const char *str_addr,
 244                            struct sockaddr_storage *sockaddr)
 245 {
 246         struct sockaddr_in6 *addr6 = (void *) sockaddr;
 247         struct sockaddr_in *addr4 = (void *) sockaddr;
 248
 249         switch (domain) {
 250         case PF_INET:
 251                 memset(addr4, 0, sizeof(*addr4));
 252                 addr4->sin_family = AF_INET;
 253                 addr4->sin_port = htons(cfg_port);
 254                 if (str_addr &&
 255                     inet_pton(AF_INET, str_addr, &(addr4->sin_addr)) != 1)
 256                         error(1, 0, "ipv4 parse error: %s", str_addr);
 257                 break;
 258         case PF_INET6:
 259                 memset(addr6, 0, sizeof(*addr6));
 260                 addr6->sin6_family = AF_INET6;
 261                 addr6->sin6_port = htons(cfg_port);
 262                 if (str_addr &&
 263                     inet_pton(AF_INET6, str_addr, &(addr6->sin6_addr)) != 1)
 264                         error(1, 0, "ipv6 parse error: %s", str_addr);
 265                 break;
 266         default:
 267                 error(1, 0, "illegal domain");
 268         }
 269 }
 270
 271 static void do_accept(int fdlisten)
 272 {
 273         if (setsockopt(fdlisten, SOL_SOCKET, SO_RCVLOWAT,
 274                        &chunk_size, sizeof(chunk_size)) == -1) {
 275                 perror("setsockopt SO_RCVLOWAT");
 276         }
 277
 278         apply_rcvsnd_buf(fdlisten);
 279
 280         while (1) {
 281                 struct sockaddr_in addr;
 282                 socklen_t addrlen = sizeof(addr);
 283                 pthread_t th;
 284                 int fd, res;
 285
 286                 fd = accept(fdlisten, (struct sockaddr *)&addr, &addrlen);
 287                 if (fd == -1) {
 288                         perror("accept");
 289                         continue;
 290                 }
 291                 res = pthread_create(&th, NULL, child_thread,
 292                                      (void *)(unsigned long)fd);
 293                 if (res) {
 294                         errno = res;
 295                         perror("pthread_create");
 296                         close(fd);
 297                 }
 298         }
 299 }
 300
 301 int main(int argc, char *argv[])
 302 {
 303         struct sockaddr_storage listenaddr, addr;
 304         unsigned int max_pacing_rate = 0;
 305         unsigned long total = 0;
 306         char *host = NULL;
 307         int fd, c, on = 1;
 308         char *buffer;
 309         int sflg = 0;
 310         int mss = 0;
 311
 312         while ((c = getopt(argc, argv, "46p:svr:w:H:zxkP:M:")) != -1) {
 313                 switch (c) {
 314                 case '4':
 315                         cfg_family = PF_INET;
 316                         cfg_alen = sizeof(struct sockaddr_in);
 317                         break;
 318                 case '6':
 319                         cfg_family = PF_INET6;
 320                         cfg_alen = sizeof(struct sockaddr_in6);
 321                         break;
 322                 case 'p':
 323                         cfg_port = atoi(optarg);
 324                         break;
 325                 case 'H':
 326                         host = optarg;
 327                         break;
 328                 case 's': /* server : listen for incoming connections */
 329                         sflg++;
 330                         break;
 331                 case 'r':
 332                         rcvbuf = atoi(optarg);
 333                         break;
 334                 case 'w':
 335                         sndbuf = atoi(optarg);
 336                         break;
 337                 case 'z':
 338                         zflg = 1;
 339                         break;
 340                 case 'M':
 341                         mss = atoi(optarg);
 342                         break;
 343                 case 'x':
 344                         xflg = 1;
 345                         break;
 346                 case 'k':
 347                         keepflag = 1;
 348                         break;
 349                 case 'P':
 350                         max_pacing_rate = atoi(optarg) ;
 351                         break;
 352                 default:
 353                         exit(1);
 354                 }
 355         }
 356         if (sflg) {
 357                 int fdlisten = socket(cfg_family, SOCK_STREAM, 0);
 358
 359                 if (fdlisten == -1) {
 360                         perror("socket");
 361                         exit(1);
 362                 }
 363                 apply_rcvsnd_buf(fdlisten);
 364                 setsockopt(fdlisten, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
 365
 366                 setup_sockaddr(cfg_family, host, &listenaddr);
 367
 368                 if (mss &&
 369                     setsockopt(fdlisten, IPPROTO_TCP, TCP_MAXSEG,
 370                                &mss, sizeof(mss)) == -1) {
 371                         perror("setsockopt TCP_MAXSEG");
 372                         exit(1);
 373                 }
 374                 if (bind(fdlisten, (const struct sockaddr *)&listenaddr, cfg_alen) == -1) {
 375                         perror("bind");
 376                         exit(1);
 377                 }
 378                 if (listen(fdlisten, 128) == -1) {
 379                         perror("listen");
 380                         exit(1);
 381                 }
 382                 do_accept(fdlisten);
 383         }
 384         buffer = mmap(NULL, chunk_size, PROT_READ | PROT_WRITE,
 385                               MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 386         if (buffer == (char *)-1) {
 387                 perror("mmap");
 388                 exit(1);
 389         }
 390
 391         fd = socket(cfg_family, SOCK_STREAM, 0);
 392         if (fd == -1) {
 393                 perror("socket");
 394                 exit(1);
 395         }
 396         apply_rcvsnd_buf(fd);
 397
 398         setup_sockaddr(cfg_family, host, &addr);
 399
 400         if (mss &&
 401             setsockopt(fd, IPPROTO_TCP, TCP_MAXSEG, &mss, sizeof(mss)) == -1) {
 402                 perror("setsockopt TCP_MAXSEG");
 403                 exit(1);
 404         }
 405         if (connect(fd, (const struct sockaddr *)&addr, cfg_alen) == -1) {
 406                 perror("connect");
 407                 exit(1);
 408         }
 409         if (max_pacing_rate &&
 410             setsockopt(fd, SOL_SOCKET, SO_MAX_PACING_RATE,
 411                        &max_pacing_rate, sizeof(max_pacing_rate)) == -1)
 412                 perror("setsockopt SO_MAX_PACING_RATE");
 413
 414         if (zflg && setsockopt(fd, SOL_SOCKET, SO_ZEROCOPY,
 415                                &on, sizeof(on)) == -1) {
 416                 perror("setsockopt SO_ZEROCOPY, (-z option disabled)");
 417                 zflg = 0;
 418         }
 419         while (total < FILE_SZ) {
 420                 long wr = FILE_SZ - total;
 421
 422                 if (wr > chunk_size)
 423                         wr = chunk_size;
 424                 /* Note : we just want to fill the pipe with 0 bytes */
 425                 wr = send(fd, buffer, wr, zflg ? MSG_ZEROCOPY : 0);
 426                 if (wr <= 0)
 427                         break;
 428                 total += wr;
 429         }
 430         close(fd);
 431         munmap(buffer, chunk_size);
 432         return 0;
 433 }