From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: [patch 05/11] tcp: BIC max increment too large Date: Fri, 23 Dec 2005 14:27:36 -0800 Message-ID: <20051223222736.GF18252@kroah.com> References: <20051109182205.294803000@press.kroah.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Chuck Wolber , torvalds@osdl.org, akpm@osdl.org, alan@lxorguk.ukuu.org.uk Return-path: To: linux-kernel@vger.kernel.org, stable@kernel.org, Arnaldo Carvalho de Melo , "David S. Miller" , netdev@vger.kernel.org Content-Disposition: inline; filename="tcp-bic-max-increment-too-large.patch" In-Reply-To: <20051223222652.GA18252@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Stephen Hemminger The max growth of BIC TCP is too large. Original code was based on BIC 1.0 and the default there was 32. Later code (2.6.13) included compensation for delayed acks, and should have reduced the default value to 16; since normally TCP gets one ack for every two packets sent. The current value of 32 makes BIC too aggressive and unfair to other flows. Submitted-by: Injong Rhee Signed-off-by: Stephen Hemminger Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_bic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- linux-2.6.14.1.orig/net/ipv4/tcp_bic.c +++ linux-2.6.14.1/net/ipv4/tcp_bic.c @@ -27,7 +27,7 @@ */ static int fast_convergence = 1; -static int max_increment = 32; +static int max_increment = 16; static int low_window = 14; static int beta = 819; /* = 819/1024 (BICTCP_BETA_SCALE) */ static int low_utilization_threshold = 153; --