From 38b50dba4704856194ac02b98e492d2349d64058 Mon Sep 17 00:00:00 2001 From: Stefano Brivio Date: Fri, 23 Apr 2021 22:22:37 +0200 Subject: passt: Spare some syscalls, add some optimisations from profiling Avoid a bunch of syscalls on forwarding paths by: - storing minimum and maximum file descriptor numbers for each protocol, fall back to SO_PROTOCOL query only on overlaps - allocating a larger receive buffer -- this can result in more coalesced packets than sendmmsg() can take (UIO_MAXIOV, i.e. 1024), so make sure we don't exceed that within a single call to protocol tap handlers - nesting the handling loop in tap_handler() in the receive loop, so that we have better chances of filling our receive buffer in fewer calls - skipping the recvfrom() in the UDP handler on EPOLLERR -- there's nothing to be done in that case and while at it: - restore the 20ms timer interval for periodic (TCP) events, I accidentally changed that to 100ms in an earlier commit - attempt using SO_ZEROCOPY for UDP -- if it's not available, sendmmsg() will succeed anyway - fix the handling of the status code from sendmmsg(), if it fails, we'll try to discard the first message, hence return 1 from the UDP handler Signed-off-by: Stefano Brivio --- tcp.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'tcp.c') diff --git a/tcp.c b/tcp.c index 330e21a..3d47f35 100644 --- a/tcp.c +++ b/tcp.c @@ -1003,6 +1003,11 @@ static void tcp_conn_from_sock(struct ctx *c, int fd) if (s == -1) return; + if (s < c->tcp.fd_min) + c->tcp.fd_min = s; + if (s > c->tcp.fd_max) + c->tcp.fd_max = s; + if (sa_l.ss_family == AF_INET) { struct sockaddr_in *sa4 = (struct sockaddr_in *)&sa_r; @@ -1445,6 +1450,9 @@ int tcp_sock_init(struct ctx *c) { in_port_t port; + c->tcp.fd_min = INT_MAX; + c->tcp.fd_max = 0; + for (port = 0; port < (1 << 15) + (1 << 14); port++) { if (c->v4 && sock_l4_add(c, 4, IPPROTO_TCP, port) < 0) return -1; -- cgit v1.2.3