From 192dc405f3080f1f7d8e90f638dc08c0e5a803a2 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 16 Apr 2018 10:33:39 -0700 Subject: selftests: net: add tcp_mmap program This is a reference program showing how mmap() can be used on TCP flows to implement receive zero copy. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- tools/testing/selftests/net/tcp_mmap.c | 437 +++++++++++++++++++++++++++++++++ 1 file changed, 437 insertions(+) create mode 100644 tools/testing/selftests/net/tcp_mmap.c (limited to 'tools/testing/selftests/net/tcp_mmap.c') diff --git a/tools/testing/selftests/net/tcp_mmap.c b/tools/testing/selftests/net/tcp_mmap.c new file mode 100644 index 000000000000..dea342fe6f4e --- /dev/null +++ b/tools/testing/selftests/net/tcp_mmap.c @@ -0,0 +1,437 @@ +/* + * Copyright 2018 Google Inc. + * Author: Eric Dumazet (edumazet@google.com) + * + * Reference program demonstrating tcp mmap() usage, + * and SO_RCVLOWAT hints for receiver. + * + * Note : NIC with header split is needed to use mmap() on TCP : + * Each incoming frame must be a multiple of PAGE_SIZE bytes of TCP payload. + * + * How to use on loopback interface : + * + * ifconfig lo mtu 61512 # 15*4096 + 40 (ipv6 header) + 32 (TCP with TS option header) + * tcp_mmap -s -z & + * tcp_mmap -H ::1 -z + * + * Or leave default lo mtu, but use -M option to set TCP_MAXSEG option to (4096 + 12) + * (4096 : page size on x86, 12: TCP TS option length) + * tcp_mmap -s -z -M $((4096+12)) & + * tcp_mmap -H ::1 -z -M $((4096+12)) + * + * Note: -z option on sender uses MSG_ZEROCOPY, which forces a copy when packets go through loopback interface. + * We might use sendfile() instead, but really this test program is about mmap(), for receivers ;) + * + * $ ./tcp_mmap -s & # Without mmap() + * $ for i in {1..4}; do ./tcp_mmap -H ::1 -z ; done + * received 32768 MB (0 % mmap'ed) in 14.1157 s, 19.4732 Gbit + * cpu usage user:0.057 sys:7.815, 240.234 usec per MB, 65531 c-switches + * received 32768 MB (0 % mmap'ed) in 14.6833 s, 18.7204 Gbit + * cpu usage user:0.043 sys:8.103, 248.596 usec per MB, 65524 c-switches + * received 32768 MB (0 % mmap'ed) in 11.143 s, 24.6682 Gbit + * cpu usage user:0.044 sys:6.576, 202.026 usec per MB, 65519 c-switches + * received 32768 MB (0 % mmap'ed) in 14.9056 s, 18.4413 Gbit + * cpu usage user:0.036 sys:8.193, 251.129 usec per MB, 65530 c-switches + * $ kill %1 # kill tcp_mmap server + * + * $ ./tcp_mmap -s -z & # With mmap() + * $ for i in {1..4}; do ./tcp_mmap -H ::1 -z ; done + * received 32768 MB (99.9939 % mmap'ed) in 6.73792 s, 40.7956 Gbit + * cpu usage user:0.045 sys:2.827, 87.6465 usec per MB, 65532 c-switches + * received 32768 MB (99.9939 % mmap'ed) in 7.26732 s, 37.8238 Gbit + * cpu usage user:0.037 sys:3.087, 95.3369 usec per MB, 65532 c-switches + * received 32768 MB (99.9939 % mmap'ed) in 7.61661 s, 36.0893 Gbit + * cpu usage user:0.046 sys:3.559, 110.016 usec per MB, 65529 c-switches + * received 32768 MB (99.9939 % mmap'ed) in 7.43764 s, 36.9577 Gbit + * cpu usage user:0.035 sys:3.467, 106.873 usec per MB, 65530 c-switches + * + * License (GPLv2): + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. * See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. + */ +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#ifndef MSG_ZEROCOPY +#define MSG_ZEROCOPY 0x4000000 +#endif + +#define FILE_SZ (1UL << 35) +static int cfg_family = AF_INET6; +static socklen_t cfg_alen = sizeof(struct sockaddr_in6); +static int cfg_port = 8787; + +static int rcvbuf; /* Default: autotuning. Can be set with -r option */ +static int sndbuf; /* Default: autotuning. Can be set with -w option */ +static int zflg; /* zero copy option. (MSG_ZEROCOPY for sender, mmap() for receiver */ +static int xflg; /* hash received data (simple xor) (-h option) */ +static int keepflag; /* -k option: receiver shall keep all received file in memory (no munmap() calls) */ + +static int chunk_size = 512*1024; + +unsigned long htotal; + +static inline void prefetch(const void *x) +{ +#if defined(__x86_64__) + asm volatile("prefetcht0 %P0" : : "m" (*(const char *)x)); +#endif +} + +void hash_zone(void *zone, unsigned int length) +{ + unsigned long temp = htotal; + + while (length >= 8*sizeof(long)) { + prefetch(zone + 384); + temp ^= *(unsigned long *)zone; + temp ^= *(unsigned long *)(zone + sizeof(long)); + temp ^= *(unsigned long *)(zone + 2*sizeof(long)); + temp ^= *(unsigned long *)(zone + 3*sizeof(long)); + temp ^= *(unsigned long *)(zone + 4*sizeof(long)); + temp ^= *(unsigned long *)(zone + 5*sizeof(long)); + temp ^= *(unsigned long *)(zone + 6*sizeof(long)); + temp ^= *(unsigned long *)(zone + 7*sizeof(long)); + zone += 8*sizeof(long); + length -= 8*sizeof(long); + } + while (length >= 1) { + temp ^= *(unsigned char *)zone; + zone += 1; + length--; + } + htotal = temp; +} + +void *child_thread(void *arg) +{ + unsigned long total_mmap = 0, total = 0; + unsigned long delta_usec; + int flags = MAP_SHARED; + struct timeval t0, t1; + char *buffer = NULL; + void *oaddr = NULL; + double throughput; + struct rusage ru; + int lu, fd; + + fd = (int)(unsigned long)arg; + + gettimeofday(&t0, NULL); + + fcntl(fd, F_SETFL, O_NDELAY); + buffer = malloc(chunk_size); + if (!buffer) { + perror("malloc"); + goto error; + } + while (1) { + struct pollfd pfd = { .fd = fd, .events = POLLIN, }; + int sub; + + poll(&pfd, 1, 10000); + if (zflg) { + void *naddr; + + naddr = mmap(oaddr, chunk_size, PROT_READ, flags, fd, 0); + if (naddr == (void *)-1) { + if (errno == EAGAIN) { + /* That is if SO_RCVLOWAT is buggy */ + usleep(1000); + continue; + } + if (errno == EINVAL) { + flags = MAP_SHARED; + oaddr = NULL; + goto fallback; + } + if (errno != EIO) + perror("mmap()"); + break; + } + total_mmap += chunk_size; + if (xflg) + hash_zone(naddr, chunk_size); + total += chunk_size; + if (!keepflag) { + flags |= MAP_FIXED; + oaddr = naddr; + } + continue; + } +fallback: + sub = 0; + while (sub < chunk_size) { + lu = read(fd, buffer + sub, chunk_size - sub); + if (lu == 0) + goto end; + if (lu < 0) + break; + if (xflg) + hash_zone(buffer + sub, lu); + total += lu; + sub += lu; + } + } +end: + gettimeofday(&t1, NULL); + delta_usec = (t1.tv_sec - t0.tv_sec) * 1000000 + t1.tv_usec - t0.tv_usec; + + throughput = 0; + if (delta_usec) + throughput = total * 8.0 / (double)delta_usec / 1000.0; + getrusage(RUSAGE_THREAD, &ru); + if (total > 1024*1024) { + unsigned long total_usec; + unsigned long mb = total >> 20; + total_usec = 1000000*ru.ru_utime.tv_sec + ru.ru_utime.tv_usec + + 1000000*ru.ru_stime.tv_sec + ru.ru_stime.tv_usec; + printf("received %lg MB (%lg %% mmap'ed) in %lg s, %lg Gbit\n" + " cpu usage user:%lg sys:%lg, %lg usec per MB, %lu c-switches\n", + total / (1024.0 * 1024.0), + 100.0*total_mmap/total, + (double)delta_usec / 1000000.0, + throughput, + (double)ru.ru_utime.tv_sec + (double)ru.ru_utime.tv_usec / 1000000.0, + (double)ru.ru_stime.tv_sec + (double)ru.ru_stime.tv_usec / 1000000.0, + (double)total_usec/mb, + ru.ru_nvcsw); + } +error: + free(buffer); + close(fd); + pthread_exit(0); +} + +static void apply_rcvsnd_buf(int fd) +{ + if (rcvbuf && setsockopt(fd, SOL_SOCKET, + SO_RCVBUF, &rcvbuf, sizeof(rcvbuf)) == -1) { + perror("setsockopt SO_RCVBUF"); + } + + if (sndbuf && setsockopt(fd, SOL_SOCKET, + SO_SNDBUF, &sndbuf, sizeof(sndbuf)) == -1) { + perror("setsockopt SO_SNDBUF"); + } +} + + +static void setup_sockaddr(int domain, const char *str_addr, + struct sockaddr_storage *sockaddr) +{ + struct sockaddr_in6 *addr6 = (void *) sockaddr; + struct sockaddr_in *addr4 = (void *) sockaddr; + + switch (domain) { + case PF_INET: + memset(addr4, 0, sizeof(*addr4)); + addr4->sin_family = AF_INET; + addr4->sin_port = htons(cfg_port); + if (str_addr && + inet_pton(AF_INET, str_addr, &(addr4->sin_addr)) != 1) + error(1, 0, "ipv4 parse error: %s", str_addr); + break; + case PF_INET6: + memset(addr6, 0, sizeof(*addr6)); + addr6->sin6_family = AF_INET6; + addr6->sin6_port = htons(cfg_port); + if (str_addr && + inet_pton(AF_INET6, str_addr, &(addr6->sin6_addr)) != 1) + error(1, 0, "ipv6 parse error: %s", str_addr); + break; + default: + error(1, 0, "illegal domain"); + } +} + +static void do_accept(int fdlisten) +{ + if (setsockopt(fdlisten, SOL_SOCKET, SO_RCVLOWAT, + &chunk_size, sizeof(chunk_size)) == -1) { + perror("setsockopt SO_RCVLOWAT"); + } + + apply_rcvsnd_buf(fdlisten); + + while (1) { + struct sockaddr_in addr; + socklen_t addrlen = sizeof(addr); + pthread_t th; + int fd, res; + + fd = accept(fdlisten, (struct sockaddr *)&addr, &addrlen); + if (fd == -1) { + perror("accept"); + continue; + } + res = pthread_create(&th, NULL, child_thread, + (void *)(unsigned long)fd); + if (res) { + errno = res; + perror("pthread_create"); + close(fd); + } + } +} + +int main(int argc, char *argv[]) +{ + struct sockaddr_storage listenaddr, addr; + unsigned int max_pacing_rate = 0; + unsigned long total = 0; + char *host = NULL; + int fd, c, on = 1; + char *buffer; + int sflg = 0; + int mss = 0; + + while ((c = getopt(argc, argv, "46p:svr:w:H:zxkP:M:")) != -1) { + switch (c) { + case '4': + cfg_family = PF_INET; + cfg_alen = sizeof(struct sockaddr_in); + break; + case '6': + cfg_family = PF_INET6; + cfg_alen = sizeof(struct sockaddr_in6); + break; + case 'p': + cfg_port = atoi(optarg); + break; + case 'H': + host = optarg; + break; + case 's': /* server : listen for incoming connections */ + sflg++; + break; + case 'r': + rcvbuf = atoi(optarg); + break; + case 'w': + sndbuf = atoi(optarg); + break; + case 'z': + zflg = 1; + break; + case 'M': + mss = atoi(optarg); + break; + case 'x': + xflg = 1; + break; + case 'k': + keepflag = 1; + break; + case 'P': + max_pacing_rate = atoi(optarg) ; + break; + default: + exit(1); + } + } + if (sflg) { + int fdlisten = socket(cfg_family, SOCK_STREAM, 0); + + if (fdlisten == -1) { + perror("socket"); + exit(1); + } + apply_rcvsnd_buf(fdlisten); + setsockopt(fdlisten, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)); + + setup_sockaddr(cfg_family, host, &listenaddr); + + if (mss && + setsockopt(fdlisten, SOL_TCP, TCP_MAXSEG, &mss, sizeof(mss)) == -1) { + perror("setsockopt TCP_MAXSEG"); + exit(1); + } + if (bind(fdlisten, (const struct sockaddr *)&listenaddr, cfg_alen) == -1) { + perror("bind"); + exit(1); + } + if (listen(fdlisten, 128) == -1) { + perror("listen"); + exit(1); + } + do_accept(fdlisten); + } + buffer = mmap(NULL, chunk_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + if (buffer == (char *)-1) { + perror("mmap"); + exit(1); + } + + fd = socket(AF_INET6, SOCK_STREAM, 0); + if (fd == -1) { + perror("socket"); + exit(1); + } + apply_rcvsnd_buf(fd); + + setup_sockaddr(cfg_family, host, &addr); + + if (mss && + setsockopt(fd, SOL_TCP, TCP_MAXSEG, &mss, sizeof(mss)) == -1) { + perror("setsockopt TCP_MAXSEG"); + exit(1); + } + if (connect(fd, (const struct sockaddr *)&addr, cfg_alen) == -1) { + perror("connect"); + exit(1); + } + if (max_pacing_rate && + setsockopt(fd, SOL_SOCKET, SO_MAX_PACING_RATE, + &max_pacing_rate, sizeof(max_pacing_rate)) == -1) + perror("setsockopt SO_MAX_PACING_RATE"); + + if (zflg && setsockopt(fd, SOL_SOCKET, SO_ZEROCOPY, + &on, sizeof(on)) == -1) { + perror("setsockopt SO_ZEROCOPY, (-z option disabled)"); + zflg = 0; + } + while (total < FILE_SZ) { + long wr = FILE_SZ - total; + + if (wr > chunk_size) + wr = chunk_size; + /* Note : we just want to fill the pipe with 0 bytes */ + wr = send(fd, buffer, wr, zflg ? MSG_ZEROCOPY : 0); + if (wr <= 0) + break; + total += wr; + } + close(fd); + munmap(buffer, chunk_size); + return 0; +} -- cgit v1.2.3-59-g8ed1b