From: Fan Du Date: Fri, 6 Mar 2015 03:18:23 +0000 (+0800) Subject: ipv4: Use binary search to choose tcp PMTU probe_size X-Git-Tag: omap-for-v4.1/fixes-rc1~141^2~323^2~2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6b58e0a5f32dedb609438bb9c9c82aa6e23381f2;p=pandora-kernel.git 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 --- diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h index 1085e12f940f..e051d399fa17 100644 --- a/include/net/netns/ipv4.h +++ b/include/net/netns/ipv4.h @@ -87,6 +87,7 @@ struct netns_ipv4 { int sysctl_tcp_fwmark_accept; int sysctl_tcp_mtu_probing; int sysctl_tcp_base_mss; + int sysctl_tcp_probe_threshold; struct ping_group_range ping_group_range; diff --git a/include/net/tcp.h b/include/net/tcp.h index 834089b0cffc..1ad82e334e27 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -67,6 +67,9 @@ void tcp_time_wait(struct sock *sk, int state, int timeo); /* The least MTU to use for probing */ #define TCP_BASE_MSS 1024 +/* Specify interval when tcp mtu probing will stop */ +#define TCP_PROBE_THRESHOLD 8 + /* After receiving this amount of duplicate ACKs fast retransmit starts. */ #define TCP_FASTRETRANS_THRESH 3 Reading git-diff-tree failed