From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jesper Dangaard Brouer Subject: Re: [PATCH] tcp: sysctl for initial receive window Date: Fri, 21 Sep 2012 19:34:33 +0200 Message-ID: <1348248873.3103.57.camel@localhost> References: <20120921085502.4534.20232.stgit@dragon> <1348241111.2669.580.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, Nandita Dukkipati To: Eric Dumazet Return-path: Received: from mx1.redhat.com ([209.132.183.28]:36823 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932087Ab2IURei (ORCPT ); Fri, 21 Sep 2012 13:34:38 -0400 In-Reply-To: <1348241111.2669.580.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: On Fri, 2012-09-21 at 17:25 +0200, Eric Dumazet wrote: > On Fri, 2012-09-21 at 10:55 +0200, Jesper Dangaard Brouer wrote: > > Make it possible to adjust the TCP default initial advertised receive > > window, via sysctl /proc/sys/net/ipv4/tcp_init_recv_window. > > > > The window size is this value multiplied by the MSS of the connection. > > The default value is (still) 10, as descibed in commit 356f039822b > > (TCP: increase default initial receive window.) > > > > Allow minimum value of 1, but recommend against setting value below 2 > > in the documentation. > > > > Its possible to control/override this value per route table entry via > > the iproute2 option initrwnd. Having the global default exported via > > sysctl, helps determine the default setting, and make is easier to > > adjust. > > I was wondering why its not symmetric : > > If we add a sysctl for initial receive window, we need another one for > initial send window ? Yes, that was also part of my plan (I just didn't have time to complete it). I'll implement the sysctl for initial congestion window, next week. Just wanted some initial feedback, on if this sysctl approach is acceptable or not. -- Best regards, Jesper Dangaard Brouer MSc.CS, Sr. Network Kernel Developer at Red Hat Author of http://www.iptv-analyzer.org LinkedIn: http://www.linkedin.com/in/brouer