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, 4 May 2001 14:37:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 4 May 2001 14:37:07 -0400 Received: from dns-229.dhcp-248.nai.com ([161.69.248.229]:52158 "HELO mcafee-labs.nai.com") by vger.kernel.org with SMTP id ; Fri, 4 May 2001 14:36:14 -0400 Message-ID: X-Mailer: XFMail 1.4.7 on Linux X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: <3AF2F09C.C5731842@chromium.com> Date: Fri, 04 May 2001 11:38:50 -0700 (PDT) From: Davide Libenzi To: Fabio Riccardi Subject: Re: X15 alpha release: as fast as TUX but in user space Cc: David_J_Morse@Dell.com, "Timothy D. Witham" , Andrew Morton , Christopher Smith , Alan Cox , linux-kernel@vger.kernel.org, mingo@elte.hu Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 04-May-2001 Fabio Riccardi wrote: > ok, I'm totally ignorant here, what is a pipelined request? http://www.w3.org/Protocols/HTTP/Performance/Pipeline.html A pipelined application implementation buffers its output before writing it to the underlying TCP stack, roughly equivalent to what the Nagle algorithm does for telnet connections. These two buffering algorithms tend to interfere, and using them together will often cause very significant performance degradation. For each connection, the server maintains a response buffer that it flushes either when full, or when there is no more requests coming in on that connection, or before it goes idle. This buffering enables aggregating responses (for example, cache validation responses) into fewer packets even on a high-speed network, and saving CPU time for the server. - Davide