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 (1ULL << 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 size_t chunk_size = 512*1024;
86
87 static size_t map_align;
88
89 unsigned long htotal;
90
prefetch(const void * x)91 static inline void prefetch(const void *x)
92 {
93 #if defined(__x86_64__)
94 asm volatile("prefetcht0 %P0" : : "m" (*(const char *)x));
95 #endif
96 }
97
hash_zone(void * zone,unsigned int length)98 void hash_zone(void *zone, unsigned int length)
99 {
100 unsigned long temp = htotal;
101
102 while (length >= 8*sizeof(long)) {
103 prefetch(zone + 384);
104 temp ^= *(unsigned long *)zone;
105 temp ^= *(unsigned long *)(zone + sizeof(long));
106 temp ^= *(unsigned long *)(zone + 2*sizeof(long));
107 temp ^= *(unsigned long *)(zone + 3*sizeof(long));
108 temp ^= *(unsigned long *)(zone + 4*sizeof(long));
109 temp ^= *(unsigned long *)(zone + 5*sizeof(long));
110 temp ^= *(unsigned long *)(zone + 6*sizeof(long));
111 temp ^= *(unsigned long *)(zone + 7*sizeof(long));
112 zone += 8*sizeof(long);
113 length -= 8*sizeof(long);
114 }
115 while (length >= 1) {
116 temp ^= *(unsigned char *)zone;
117 zone += 1;
118 length--;
119 }
120 htotal = temp;
121 }
122
123 #define ALIGN_UP(x, align_to) (((x) + ((align_to)-1)) & ~((align_to)-1))
124 #define ALIGN_PTR_UP(p, ptr_align_to) ((typeof(p))ALIGN_UP((unsigned long)(p), ptr_align_to))
125
child_thread(void * arg)126 void *child_thread(void *arg)
127 {
128 unsigned long total_mmap = 0, total = 0;
129 struct tcp_zerocopy_receive zc;
130 unsigned long delta_usec;
131 int flags = MAP_SHARED;
132 struct timeval t0, t1;
133 char *buffer = NULL;
134 void *raddr = NULL;
135 void *addr = NULL;
136 double throughput;
137 struct rusage ru;
138 int lu, fd;
139
140 fd = (int)(unsigned long)arg;
141
142 gettimeofday(&t0, NULL);
143
144 fcntl(fd, F_SETFL, O_NDELAY);
145 buffer = malloc(chunk_size);
146 if (!buffer) {
147 perror("malloc");
148 goto error;
149 }
150 if (zflg) {
151 raddr = mmap(NULL, chunk_size + map_align, PROT_READ, flags, fd, 0);
152 if (raddr == (void *)-1) {
153 perror("mmap");
154 zflg = 0;
155 } else {
156 addr = ALIGN_PTR_UP(raddr, map_align);
157 }
158 }
159 while (1) {
160 struct pollfd pfd = { .fd = fd, .events = POLLIN, };
161 int sub;
162
163 poll(&pfd, 1, 10000);
164 if (zflg) {
165 socklen_t zc_len = sizeof(zc);
166 int res;
167
168 zc.address = (__u64)((unsigned long)addr);
169 zc.length = chunk_size;
170 zc.recv_skip_hint = 0;
171 res = getsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE,
172 &zc, &zc_len);
173 if (res == -1)
174 break;
175
176 if (zc.length) {
177 assert(zc.length <= chunk_size);
178 total_mmap += zc.length;
179 if (xflg)
180 hash_zone(addr, zc.length);
181 total += zc.length;
182 }
183 if (zc.recv_skip_hint) {
184 assert(zc.recv_skip_hint <= chunk_size);
185 lu = read(fd, buffer, zc.recv_skip_hint);
186 if (lu > 0) {
187 if (xflg)
188 hash_zone(buffer, lu);
189 total += lu;
190 }
191 }
192 continue;
193 }
194 sub = 0;
195 while (sub < chunk_size) {
196 lu = read(fd, buffer + sub, chunk_size - sub);
197 if (lu == 0)
198 goto end;
199 if (lu < 0)
200 break;
201 if (xflg)
202 hash_zone(buffer + sub, lu);
203 total += lu;
204 sub += lu;
205 }
206 }
207 end:
208 gettimeofday(&t1, NULL);
209 delta_usec = (t1.tv_sec - t0.tv_sec) * 1000000 + t1.tv_usec - t0.tv_usec;
210
211 throughput = 0;
212 if (delta_usec)
213 throughput = total * 8.0 / (double)delta_usec / 1000.0;
214 getrusage(RUSAGE_THREAD, &ru);
215 if (total > 1024*1024) {
216 unsigned long total_usec;
217 unsigned long mb = total >> 20;
218 total_usec = 1000000*ru.ru_utime.tv_sec + ru.ru_utime.tv_usec +
219 1000000*ru.ru_stime.tv_sec + ru.ru_stime.tv_usec;
220 printf("received %lg MB (%lg %% mmap'ed) in %lg s, %lg Gbit\n"
221 " cpu usage user:%lg sys:%lg, %lg usec per MB, %lu c-switches\n",
222 total / (1024.0 * 1024.0),
223 100.0*total_mmap/total,
224 (double)delta_usec / 1000000.0,
225 throughput,
226 (double)ru.ru_utime.tv_sec + (double)ru.ru_utime.tv_usec / 1000000.0,
227 (double)ru.ru_stime.tv_sec + (double)ru.ru_stime.tv_usec / 1000000.0,
228 (double)total_usec/mb,
229 ru.ru_nvcsw);
230 }
231 error:
232 free(buffer);
233 close(fd);
234 if (zflg)
235 munmap(raddr, chunk_size + map_align);
236 pthread_exit(0);
237 }
238
apply_rcvsnd_buf(int fd)239 static void apply_rcvsnd_buf(int fd)
240 {
241 if (rcvbuf && setsockopt(fd, SOL_SOCKET,
242 SO_RCVBUF, &rcvbuf, sizeof(rcvbuf)) == -1) {
243 perror("setsockopt SO_RCVBUF");
244 }
245
246 if (sndbuf && setsockopt(fd, SOL_SOCKET,
247 SO_SNDBUF, &sndbuf, sizeof(sndbuf)) == -1) {
248 perror("setsockopt SO_SNDBUF");
249 }
250 }
251
252
setup_sockaddr(int domain,const char * str_addr,struct sockaddr_storage * sockaddr)253 static void setup_sockaddr(int domain, const char *str_addr,
254 struct sockaddr_storage *sockaddr)
255 {
256 struct sockaddr_in6 *addr6 = (void *) sockaddr;
257 struct sockaddr_in *addr4 = (void *) sockaddr;
258
259 switch (domain) {
260 case PF_INET:
261 memset(addr4, 0, sizeof(*addr4));
262 addr4->sin_family = AF_INET;
263 addr4->sin_port = htons(cfg_port);
264 if (str_addr &&
265 inet_pton(AF_INET, str_addr, &(addr4->sin_addr)) != 1)
266 error(1, 0, "ipv4 parse error: %s", str_addr);
267 break;
268 case PF_INET6:
269 memset(addr6, 0, sizeof(*addr6));
270 addr6->sin6_family = AF_INET6;
271 addr6->sin6_port = htons(cfg_port);
272 if (str_addr &&
273 inet_pton(AF_INET6, str_addr, &(addr6->sin6_addr)) != 1)
274 error(1, 0, "ipv6 parse error: %s", str_addr);
275 break;
276 default:
277 error(1, 0, "illegal domain");
278 }
279 }
280
do_accept(int fdlisten)281 static void do_accept(int fdlisten)
282 {
283 pthread_attr_t attr;
284
285 pthread_attr_init(&attr);
286 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
287
288 if (setsockopt(fdlisten, SOL_SOCKET, SO_RCVLOWAT,
289 &chunk_size, sizeof(chunk_size)) == -1) {
290 perror("setsockopt SO_RCVLOWAT");
291 }
292
293 apply_rcvsnd_buf(fdlisten);
294
295 while (1) {
296 struct sockaddr_in addr;
297 socklen_t addrlen = sizeof(addr);
298 pthread_t th;
299 int fd, res;
300
301 fd = accept(fdlisten, (struct sockaddr *)&addr, &addrlen);
302 if (fd == -1) {
303 perror("accept");
304 continue;
305 }
306 res = pthread_create(&th, &attr, child_thread,
307 (void *)(unsigned long)fd);
308 if (res) {
309 errno = res;
310 perror("pthread_create");
311 close(fd);
312 }
313 }
314 }
315
316 /* Each thread should reserve a big enough vma to avoid
317 * spinlock collisions in ptl locks.
318 * This size is 2MB on x86_64, and is exported in /proc/meminfo.
319 */
default_huge_page_size(void)320 static unsigned long default_huge_page_size(void)
321 {
322 FILE *f = fopen("/proc/meminfo", "r");
323 unsigned long hps = 0;
324 size_t linelen = 0;
325 char *line = NULL;
326
327 if (!f)
328 return 0;
329 while (getline(&line, &linelen, f) > 0) {
330 if (sscanf(line, "Hugepagesize: %lu kB", &hps) == 1) {
331 hps <<= 10;
332 break;
333 }
334 }
335 free(line);
336 fclose(f);
337 return hps;
338 }
339
main(int argc,char * argv[])340 int main(int argc, char *argv[])
341 {
342 struct sockaddr_storage listenaddr, addr;
343 unsigned int max_pacing_rate = 0;
344 size_t total = 0;
345 char *host = NULL;
346 int fd, c, on = 1;
347 char *buffer;
348 int sflg = 0;
349 int mss = 0;
350
351 while ((c = getopt(argc, argv, "46p:svr:w:H:zxkP:M:C:a:")) != -1) {
352 switch (c) {
353 case '4':
354 cfg_family = PF_INET;
355 cfg_alen = sizeof(struct sockaddr_in);
356 break;
357 case '6':
358 cfg_family = PF_INET6;
359 cfg_alen = sizeof(struct sockaddr_in6);
360 break;
361 case 'p':
362 cfg_port = atoi(optarg);
363 break;
364 case 'H':
365 host = optarg;
366 break;
367 case 's': /* server : listen for incoming connections */
368 sflg++;
369 break;
370 case 'r':
371 rcvbuf = atoi(optarg);
372 break;
373 case 'w':
374 sndbuf = atoi(optarg);
375 break;
376 case 'z':
377 zflg = 1;
378 break;
379 case 'M':
380 mss = atoi(optarg);
381 break;
382 case 'x':
383 xflg = 1;
384 break;
385 case 'k':
386 keepflag = 1;
387 break;
388 case 'P':
389 max_pacing_rate = atoi(optarg) ;
390 break;
391 case 'C':
392 chunk_size = atol(optarg);
393 break;
394 case 'a':
395 map_align = atol(optarg);
396 break;
397 default:
398 exit(1);
399 }
400 }
401 if (!map_align) {
402 map_align = default_huge_page_size();
403 /* if really /proc/meminfo is not helping,
404 * we use the default x86_64 hugepagesize.
405 */
406 if (!map_align)
407 map_align = 2*1024*1024;
408 }
409 if (sflg) {
410 int fdlisten = socket(cfg_family, SOCK_STREAM, 0);
411
412 if (fdlisten == -1) {
413 perror("socket");
414 exit(1);
415 }
416 apply_rcvsnd_buf(fdlisten);
417 setsockopt(fdlisten, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
418
419 setup_sockaddr(cfg_family, host, &listenaddr);
420
421 if (mss &&
422 setsockopt(fdlisten, IPPROTO_TCP, TCP_MAXSEG,
423 &mss, sizeof(mss)) == -1) {
424 perror("setsockopt TCP_MAXSEG");
425 exit(1);
426 }
427 if (bind(fdlisten, (const struct sockaddr *)&listenaddr, cfg_alen) == -1) {
428 perror("bind");
429 exit(1);
430 }
431 if (listen(fdlisten, 128) == -1) {
432 perror("listen");
433 exit(1);
434 }
435 do_accept(fdlisten);
436 }
437 buffer = mmap(NULL, chunk_size, PROT_READ | PROT_WRITE,
438 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
439 if (buffer == (char *)-1) {
440 perror("mmap");
441 exit(1);
442 }
443
444 fd = socket(cfg_family, SOCK_STREAM, 0);
445 if (fd == -1) {
446 perror("socket");
447 exit(1);
448 }
449 apply_rcvsnd_buf(fd);
450
451 setup_sockaddr(cfg_family, host, &addr);
452
453 if (mss &&
454 setsockopt(fd, IPPROTO_TCP, TCP_MAXSEG, &mss, sizeof(mss)) == -1) {
455 perror("setsockopt TCP_MAXSEG");
456 exit(1);
457 }
458 if (connect(fd, (const struct sockaddr *)&addr, cfg_alen) == -1) {
459 perror("connect");
460 exit(1);
461 }
462 if (max_pacing_rate &&
463 setsockopt(fd, SOL_SOCKET, SO_MAX_PACING_RATE,
464 &max_pacing_rate, sizeof(max_pacing_rate)) == -1)
465 perror("setsockopt SO_MAX_PACING_RATE");
466
467 if (zflg && setsockopt(fd, SOL_SOCKET, SO_ZEROCOPY,
468 &on, sizeof(on)) == -1) {
469 perror("setsockopt SO_ZEROCOPY, (-z option disabled)");
470 zflg = 0;
471 }
472 while (total < FILE_SZ) {
473 ssize_t wr = FILE_SZ - total;
474
475 if (wr > chunk_size)
476 wr = chunk_size;
477 /* Note : we just want to fill the pipe with 0 bytes */
478 wr = send(fd, buffer, wr, zflg ? MSG_ZEROCOPY : 0);
479 if (wr <= 0)
480 break;
481 total += wr;
482 }
483 close(fd);
484 munmap(buffer, chunk_size);
485 return 0;
486 }
487