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 --- udp.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'udp.h') diff --git a/udp.h b/udp.h index 0179fa2..b9ac2e0 100644 --- a/udp.h +++ b/udp.h @@ -1,4 +1,19 @@ +#ifndef UDP_H +#define UDP_H + void udp_sock_handler(struct ctx *c, int s, uint32_t events); int udp_tap_handler(struct ctx *c, int af, void *addr, struct tap_msg *msg, int count); int udp_sock_init(struct ctx *c); + +/** + * struct udp_ctx - Execution context for UDP + * @fd_min: Lowest file descriptor number for UDP ever used + * @fd_max: Highest file descriptor number for UDP ever used + */ +struct udp_ctx { + int fd_min; + int fd_max; +}; + +#endif /* UDP_H */ -- cgit v1.2.3