From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 9 Nov 2001 11:04:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 9 Nov 2001 11:03:56 -0500 Received: from cj46222-a.reston1.va.home.com ([65.1.136.109]:25561 "HELO sanosuke.troilus.org") by vger.kernel.org with SMTP id ; Fri, 9 Nov 2001 11:03:46 -0500 To: "David S. Miller" Cc: carlo@alinoe.com, linux-kernel@vger.kernel.org Subject: Re: [ircu-development] Slow on high-MTU (local host) connections? In-Reply-To: <20011107043425.A15045@alinoe.com> <20011106.195257.102576616.davem@redhat.com> From: Entrope Date: 09 Nov 2001 11:04:23 -0500 In-Reply-To: <20011106.195257.102576616.davem@redhat.com> Message-ID: <87r8r82ans.fsf@sanosuke.troilus.org> User-Agent: Gnus/5.0808 (Gnus v5.8.8) XEmacs/21.4 (Artificial Intelligence) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Following up on this: Carlo and I both tried disabling Nagle on the sockets (both ends). We still saw the same slow sending pattern. On one end (the "ircu" process in Carlo's original mail), the send and receive buffers (SO_SNDBUF, SO_RCVBUF) had been set to 8 KB each. If these are increased to be larger than the loopback MTU, it makes the problem go away. (On the other, "srvx" end, the buffer sizes were kept at the default.) Is this expected behavior? If so, why? (The references I've found on the web suggest that the send and receive buffer sizes would only come into play if Nagle were still enabled.) -- Entrope