From 66a67effcc5beaf8a61e1c1147c3114b02a96439 Mon Sep 17 00:00:00 2001 From: Tom Gundersen Date: Mon, 31 Mar 2014 23:28:58 +0200 Subject: [PATCH] sd-dhcp-client: --omg-optimized Passing the protocol to socket() is redundant as it will be specified again in bind(). Dropping the redundancy reduces the cost of bind() from ~30ms to ~0ms. For details see [0]. networkd in a container (i.e., with next to no network latency) can now negotiate a DHCP lease in 0.7 - 5 ms. Thanks to Kay for help with debugging and to Daniel Borkmann for the pointer to fix the problem. [0]: --- src/libsystemd-network/dhcp-network.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/src/libsystemd-network/dhcp-network.c b/src/libsystemd-network/dhcp-network.c index 29e915c47..ecc94b9be 100644 --- a/src/libsystemd-network/dhcp-network.c +++ b/src/libsystemd-network/dhcp-network.c @@ -37,8 +37,7 @@ int dhcp_network_bind_raw_socket(int index, union sockaddr_union *link) assert(index > 0); assert(link); - s = socket(AF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, - htons(ETH_P_IP)); + s = socket(AF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0); if (s < 0) return -errno; -- 2.30.2