From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f199.google.com (mail-io0-f199.google.com [209.85.223.199]) by kanga.kvack.org (Postfix) with ESMTP id A4B976B0005 for ; Thu, 26 Apr 2018 10:58:18 -0400 (EDT) Received: by mail-io0-f199.google.com with SMTP id a193-v6so18038223ioa.23 for ; Thu, 26 Apr 2018 07:58:18 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id a19-v6sor8003078itc.73.2018.04.26.07.58.17 for (Google Transport Security); Thu, 26 Apr 2018 07:58:17 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20180426145056.220325-3-edumazet@google.com> References: <20180426145056.220325-1-edumazet@google.com> <20180426145056.220325-3-edumazet@google.com> From: Soheil Hassas Yeganeh Date: Thu, 26 Apr 2018 10:57:36 -0400 Message-ID: Subject: Re: [PATCH v3 net-next 2/2] selftests: net: tcp_mmap must use TCP_ZEROCOPY_RECEIVE Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: Eric Dumazet Cc: "David S . Miller" , netdev , Andy Lutomirski , linux-kernel , linux-mm , Ka-Cheong Poon , Eric Dumazet On Thu, Apr 26, 2018 at 10:50 AM, Eric Dumazet wrote: > 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 > Cc: Soheil Hassas Yeganeh Acked-by: Soheil Hassas Yeganeh Thank you, again! > --- > tools/testing/selftests/net/tcp_mmap.c | 64 +++++++++++++++----------- > 1 file changed, 37 insertions(+), 27 deletions(-) > > diff --git a/tools/testing/selftests/net/tcp_mmap.c b/tools/testing/selftests/net/tcp_mmap.c > index dea342fe6f4e88b5709d2ac37b2fc9a2a320bf44..77f762780199ff1f69f9f6b3f18e72deddb69f5e 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; > + socklen_t zc_len = sizeof(zc); > + int res; > > - 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()"); > + 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 @@ void *child_thread(void *arg) > 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); > } > -- > 2.17.0.484.g0c8726318c-goog >