From aacb0c2e524c38d7ab48b0beb86427a36807079f Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 27 Apr 2018 08:58:09 -0700 Subject: [PATCH] selftests: net: tcp_mmap must use TCP_ZEROCOPY_RECEIVE After prior kernel change, mmap() on TCP socket only reserves VMA. We have to use getsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE, ...) to perform the transfert of pages from skbs in TCP receive queue into such VMA. struct tcp_zerocopy_receive { __u64 address; /* in: address of mapping */ __u32 length; /* in/out: number of bytes to map/mapped */ __u32 recv_skip_hint; /* out: amount of bytes to skip */ }; After a successful getsockopt(...TCP_ZEROCOPY_RECEIVE...), @length contains number of bytes that were mapped, and @recv_skip_hint contains number of bytes that should be read using conventional read()/recv()/recvmsg() system calls, to skip a sequence of bytes that can not be mapped, because not properly page aligned. Signed-off-by: Eric Dumazet Cc: Andy Lutomirski Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller --- tools/testing/selftests/net/tcp_mmap.c | 66 +++++++++++++++++++--------------- 1 file changed, 38 insertions(+), 28 deletions(-) diff --git a/tools/testing/selftests/net/tcp_mmap.c b/tools/testing/selftests/net/tcp_mmap.c index dea342f..77f7627 100644 --- a/tools/testing/selftests/net/tcp_mmap.c +++ b/tools/testing/selftests/net/tcp_mmap.c @@ -76,9 +76,10 @@ #include #include #include -#include #include #include +#include +#include #ifndef MSG_ZEROCOPY #define MSG_ZEROCOPY 0x4000000 @@ -134,11 +135,12 @@ void hash_zone(void *zone, unsigned int length) void *child_thread(void *arg) { unsigned long total_mmap = 0, total = 0; + struct tcp_zerocopy_receive zc; unsigned long delta_usec; int flags = MAP_SHARED; struct timeval t0, t1; char *buffer = NULL; - void *oaddr = NULL; + void *addr = NULL; double throughput; struct rusage ru; int lu, fd; @@ -153,41 +155,46 @@ void *child_thread(void *arg) perror("malloc"); goto error; } + if (zflg) { + addr = mmap(NULL, chunk_size, PROT_READ, flags, fd, 0); + if (addr == (void *)-1) + zflg = 0; + } 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()"); + socklen_t zc_len = sizeof(zc); + int res; + + zc.address = (__u64)addr; + zc.length = chunk_size; + zc.recv_skip_hint = 0; + res = getsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE, + &zc, &zc_len); + if (res == -1) break; + + if (zc.length) { + assert(zc.length <= chunk_size); + total_mmap += zc.length; + if (xflg) + hash_zone(addr, zc.length); + total += zc.length; } - total_mmap += chunk_size; - if (xflg) - hash_zone(naddr, chunk_size); - total += chunk_size; - if (!keepflag) { - flags |= MAP_FIXED; - oaddr = naddr; + if (zc.recv_skip_hint) { + assert(zc.recv_skip_hint <= chunk_size); + lu = read(fd, buffer, zc.recv_skip_hint); + if (lu > 0) { + if (xflg) + hash_zone(buffer, lu); + total += lu; + } } continue; } -fallback: sub = 0; while (sub < chunk_size) { lu = read(fd, buffer + sub, chunk_size - sub); @@ -228,6 +235,8 @@ end: error: free(buffer); close(fd); + if (zflg) + munmap(addr, chunk_size); pthread_exit(0); } @@ -371,7 +380,8 @@ int main(int argc, char *argv[]) setup_sockaddr(cfg_family, host, &listenaddr); if (mss && - setsockopt(fdlisten, SOL_TCP, TCP_MAXSEG, &mss, sizeof(mss)) == -1) { + setsockopt(fdlisten, IPPROTO_TCP, TCP_MAXSEG, + &mss, sizeof(mss)) == -1) { perror("setsockopt TCP_MAXSEG"); exit(1); } @@ -402,7 +412,7 @@ int main(int argc, char *argv[]) setup_sockaddr(cfg_family, host, &addr); if (mss && - setsockopt(fd, SOL_TCP, TCP_MAXSEG, &mss, sizeof(mss)) == -1) { + setsockopt(fd, IPPROTO_TCP, TCP_MAXSEG, &mss, sizeof(mss)) == -1) { perror("setsockopt TCP_MAXSEG"); exit(1); } -- 2.7.4