Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965016AbWLMQU5 (ORCPT ); Wed, 13 Dec 2006 11:20:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965017AbWLMQU5 (ORCPT ); Wed, 13 Dec 2006 11:20:57 -0500 Received: from mga02.intel.com ([134.134.136.20]:22091 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965016AbWLMQU4 (ORCPT ); Wed, 13 Dec 2006 11:20:56 -0500 X-ExtLoop1: 1 X-IronPort-AV: i="4.12,164,1165219200"; d="scan'208"; a="173988144:sNHT31290784" From: "Chen, Kenneth W" To: "'Miquel van Smoorenburg'" , Subject: RE: cfq performance gap Date: Wed, 13 Dec 2006 08:20:52 -0800 Message-ID: <000001c71ed2$a90019b0$2e81030a@amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Office Outlook 11 Thread-Index: AccenoQNNLFdbxshSYaNFxCdvQHIVAAM8jcA In-Reply-To: <457fce6a$0$334$e4fe514c@news.xs4all.nl> X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 898 Lines: 17 Miquel van Smoorenburg wrote on Wednesday, December 13, 2006 1:57 AM > Chen, Kenneth W wrote: > >This rawio test plows through sequential I/O and modulo each small record > >over number of threads. So each thread appears to be non-contiguous within > >its own process context, overall request hitting the device are sequential. > >I can't see how any application does that kind of I/O pattern. > > A NNTP server that has many incoming connections, handled by > multiple threads, that stores the data in cylic buffers ? Then whichever the thread that dumps the buffer content to the storage will do one large contiguous I/O. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/