From d4c4c4c5943feb46aad7f5dad5bcf573933a62a2 Mon Sep 17 00:00:00 2001 From: Ben Pfaff Date: Thu, 15 Mar 2012 21:15:38 -0700 Subject: netlink-socket: Increase Netlink socket receive buffer size. Open vSwitch userspace can set up flows at a high rate, but it is somewhat "bursty" in opportunities to set up flows, by which I mean that OVS sets up a batch of flows, then goes off and does some other work for a while, then sets up another batch of flows, and so on. The result is that, if a large number of packets that need flow setups come in all at once, then some of them can overflow the relatively small kernel-to-user buffers. This commit increases the kernel-to-user buffers from the default of approximately 120 kB each to 1 MB each. In one somewhat synthetic test case that I ran based on an "hping3" that generated a load of about 20,000 new flows per second (including both requests and replies), this reduced the packets dropped at the kernel-to-user interface from about 30% to none. I expect that it will similarly improve packet loss in workloads where flow arrival is not easily predictable. (This has little effect on workloads generated by "ovs-benchmark rate" because that benchmark is effectively "self-clocking", that is, a new flow is triggered only by a reply to a request made earlier, which means that the number of buffered packets at any given has a known, constant upper limit.) Bug #10210. Signed-off-by: Ben Pfaff --- include/sparse/sys/socket.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/sparse/sys/socket.h b/include/sparse/sys/socket.h index 89e3c2dc..1ed195b2 100644 --- a/include/sparse/sys/socket.h +++ b/include/sparse/sys/socket.h @@ -1,5 +1,5 @@ /* - * Copyright (c) 2011 Nicira Networks. + * Copyright (c) 2011, 2012 Nicira Networks. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -74,7 +74,8 @@ enum { SO_SNDBUF, SO_SNDLOWAT, SO_SNDTIMEO, - SO_TYPE + SO_TYPE, + SO_RCVBUFFORCE }; enum { -- cgit v1.2.3