From 81146ec1b85067e70b71e81b5ecd9998ce054c0e Mon Sep 17 00:00:00 2001 From: Ilpo Järvinen Date: Sat, 19 Feb 2011 21:52:41 +0000 Subject: tcp: document tcp_max_ssthresh (Limited Slow-Start) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Base on Ilpo's patch about documenting tcp_max_ssthresh. (see http://marc.info/?l=linux-netdev&m=117950581307310&w=2) According to errata of RFC3742, fix the number of segments increased during RTT time. Just to state the occasion to use this parameter, But about how to set parameter value, maybe some others can do it. Signed-off-by: Ilpo Järvinen Signed-off-by: Shan Wei Signed-off-by: David S. Miller --- Documentation/networking/ip-sysctl.txt | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'Documentation') diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index ac3b4a726a1a..d3d653a5f9b9 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -280,6 +280,17 @@ tcp_max_orphans - INTEGER more aggressively. Let me to remind again: each orphan eats up to ~64K of unswappable memory. +tcp_max_ssthresh - INTEGER + Limited Slow-Start for TCP with large congestion windows (cwnd) defined in + RFC3742. Limited slow-start is a mechanism to limit growth of the cwnd + on the region where cwnd is larger than tcp_max_ssthresh. TCP increases cwnd + by at most tcp_max_ssthresh segments, and by at least tcp_max_ssthresh/2 + segments per RTT when the cwnd is above tcp_max_ssthresh. + If TCP connection increased cwnd to thousands (or tens of thousands) segments, + and thousands of packets were being dropped during slow-start, you can set + tcp_max_ssthresh to improve performance for new TCP connection. + Default: 0 (off) + tcp_max_syn_backlog - INTEGER Maximal number of remembered connection requests, which are still did not receive an acknowledgment from connecting client. -- cgit v1.2.3-59-g8ed1b