From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Graf Subject: Re: [PATCH] sctp: Do not account for sizeof(struct sk_buff) in estimated rwnd Date: Mon, 19 Dec 2011 18:19:36 -0500 Message-ID: <20111219231936.GA21801@canuck.infradead.org> References: <1324303900-8360-1-git-send-email-tgraf@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-sctp@vger.kernel.org, "David S. Miller" , netdev@vger.kernel.org To: Vladislav Yasevich Return-path: Received: from merlin.infradead.org ([205.233.59.134]:38491 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752718Ab1LSXTj (ORCPT ); Mon, 19 Dec 2011 18:19:39 -0500 Content-Disposition: inline In-Reply-To: <1324303900-8360-1-git-send-email-tgraf@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, Dec 19, 2011 at 03:11:40PM +0100, Thomas Graf wrote: > Trying to reproduce this I found that with the sk_buff overhead removed, > the performance would improve significantly unless socket buffer limits > are increased. I believe this is likely to be misunderstood. What I meant is that by removing the sk_buff overhead and while using default socket buffer limits the performance increases as shown below. If socket buffers are enlarged performance differences fade until there is no longer any difference. Sorry for poor wording. > The following numbers have been gathered using a patched iperf > supporting SCTP over a live 1 Gbit ethernet network. The -l option > was used to limit DATA chunk sizes. The numbers listed are based on > the average of 3 test runs each. Default values have been used for > sk_(r|w)mem. > > Chunk > Size Unpatched No Overhead > ------------------------------------- > 4 15.2 Kbit [!] 12.2 Mbit [!] > 8 35.8 Kbit [!] 26.0 Mbit [!] > 16 95.5 Kbit [!] 54.4 Mbit [!] > 32 106.7 Mbit 102.3 Mbit > 64 189.2 Mbit 188.3 Mbit > 128 331.2 Mbit 334.8 Mbit > 256 537.7 Mbit 536.0 Mbit > 512 766.9 Mbit 766.6 Mbit > 1024 810.1 Mbit 808.6 Mbit