From 6b58e0a5f32dedb609438bb9c9c82aa6e23381f2 Mon Sep 17 00:00:00 2001 From: Fan Du Date: Fri, 6 Mar 2015 11:18:23 +0800 Subject: ipv4: Use binary search to choose tcp PMTU probe_size Current probe_size is chosen by doubling mss_cache, the probing process will end shortly with a sub-optimal mss size, and the link mtu will not be taken full advantage of, in return, this will make user to tweak tcp_base_mss with care. Use binary search to choose probe_size in a fine granularity manner, an optimal mss will be found to boost performance as its maxmium. In addition, introduce a sysctl_tcp_probe_threshold to control when probing will stop in respect to the width of search range. Test env: Docker instance with vxlan encapuslation(82599EB) iperf -c 10.0.0.24 -t 60 before this patch: 1.26 Gbits/sec After this patch: increase 26% 1.59 Gbits/sec Signed-off-by: Fan Du Acked-by: John Heffner Signed-off-by: David S. Miller --- net/ipv4/tcp_ipv4.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net/ipv4/tcp_ipv4.c') diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 5a2dfed..35790d9 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -2460,6 +2460,7 @@ static int __net_init tcp_sk_init(struct net *net) } net->ipv4.sysctl_tcp_ecn = 2; net->ipv4.sysctl_tcp_base_mss = TCP_BASE_MSS; + net->ipv4.sysctl_tcp_probe_threshold = TCP_PROBE_THRESHOLD; return 0; fail: -- cgit v1.1