From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-next] tcp: reduce memory needs of out of order queue Date: Fri, 14 Oct 2011 19:18:45 -0400 (EDT) Message-ID: <20111014.191845.232827637484150228.davem@davemloft.net> References: <20111014.034224.1197576516015404466.davem@davemloft.net> <4E985A3F.5080103@hp.com> <4E98B3B4.20406@hp.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: eric.dumazet@gmail.com, netdev@vger.kernel.org To: rick.jones2@hp.com Return-path: Received: from shards.monkeyblade.net ([198.137.202.13]:58129 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751575Ab1JNXTD (ORCPT ); Fri, 14 Oct 2011 19:19:03 -0400 In-Reply-To: <4E98B3B4.20406@hp.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Rick Jones Date: Fri, 14 Oct 2011 15:12:04 -0700 > From just a very quick look it looks like tcp_v[46]_rcv is called, > finds that the socket is owned by the user, attempts to add to the > backlog, but the path called by sk_add_backlog does not seem to make > any attempts to compress things, so when the quantity of data is << > the truesize it starts tossing babies out with the bathwater. This is why I don't believe the right fix is to add bandaids all around the TCP layer. The wastage has to be avoided at a higher level.