From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rick Jones Subject: Re: setsockopt() Date: Mon, 07 Jul 2008 16:27:14 -0700 Message-ID: <4872A652.2050709@hp.com> References: <20080707142408.43aa2a2e@extreme> <48728B09.1050801@citi.umich.edu> <48729DAD.8010400@hp.com> <20080707.160029.13296246.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: aglo@citi.umich.edu, shemminger@vyatta.com, netdev@vger.kernel.org, rees@umich.edu, bfields@fieldses.org To: David Miller Return-path: Received: from g4t0015.houston.hp.com ([15.201.24.18]:2408 "EHLO g4t0015.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754209AbYGGX1W (ORCPT ); Mon, 7 Jul 2008 19:27:22 -0400 In-Reply-To: <20080707.160029.13296246.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: David Miller wrote: > We need 2x, in order to have a full window during recovery. > > There was a measurement bug found a few months ago when the > google folks were probing in this area, which was fixed > by John Heffner. Most of which had to deal with TSO subtleties. > > -------------------- > commit 246eb2af060fc32650f07203c02bdc0456ad76c7 > Author: John Heffner > Date: Tue Apr 29 03:13:52 2008 -0700 > > tcp: Limit cwnd growth when deferring for GSO > > This fixes inappropriately large cwnd growth on sender-limited flows > when GSO is enabled, limiting cwnd growth to 64k. > > Signed-off-by: John Heffner > Signed-off-by: David S. Miller > > commit ce447eb91409225f8a488f6b7b2a1bdf7b2d884f > Author: John Heffner > Date: Tue Apr 29 03:13:02 2008 -0700 > > tcp: Allow send-limited cwnd to grow up to max_burst when gso disabled > > This changes the logic in tcp_is_cwnd_limited() so that cwnd may grow > up to tcp_max_burst() even when sk_can_gso() is false, or when > sysctl_tcp_tso_win_divisor != 0. > > Signed-off-by: John Heffner > Signed-off-by: David S. Miller > -------------------- I'll try my tests again with newer kernels since I'm not 100% certain I was trying with those commits in place. > Setting TCP socket buffer via setsockopt() is always wrong. Does that apply equally to SO_SNDBUF and SO_RCVBUF? rick jones