From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id o7B9jZrK131847 for ; Wed, 11 Aug 2010 04:45:36 -0500 Received: from lo.gmane.org (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id C186E1D72008 for ; Wed, 11 Aug 2010 02:45:59 -0700 (PDT) Received: from lo.gmane.org (lo.gmane.org [80.91.229.12]) by cuda.sgi.com with ESMTP id hVkymNpTFoAMAbEx for ; Wed, 11 Aug 2010 02:45:59 -0700 (PDT) Received: from list by lo.gmane.org with local (Exim 4.69) (envelope-from ) id 1Oj7sh-0006aR-BV for linux-xfs@oss.sgi.com; Wed, 11 Aug 2010 11:45:55 +0200 Received: from barriere.frankfurter-softwarefabrik.de ([217.11.197.1]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 11 Aug 2010 11:45:55 +0200 Received: from niemayer by barriere.frankfurter-softwarefabrik.de with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 11 Aug 2010 11:45:55 +0200 From: Peter Niemayer Subject: Re: observed significant performance improvement using "delaylog" in a real-world application Date: Wed, 11 Aug 2010 11:45:41 +0200 Message-ID: References: <201008111003.36890@zmi.at> Mime-Version: 1.0 In-Reply-To: <201008111003.36890@zmi.at> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: linux-xfs@oss.sgi.com On 08/11/2010 10:03 AM, Michael Monnerie wrote: > On Dienstag, 10. August 2010 Peter Niemayer wrote: >> 17% performance increase for our benchmark scenario > > Can you say what kind of data accesses you have? The application basically writes a large data set to ~ 100,000 files, which consists of many small messages. Each message consists of a primary key (an integer in the range of 0 to approx. 1,000,000) and an (almost random) number of data bytes (length in the range from 10 to ~1000 byte). For each message, the application opens the file that is determined by the primary key with O_APPEND, write()s the data bytes to the file. Then it closes the file. (There are usually a few to many messages per primary key / file). The application runs 4 threads in parallel to spread the above action over 4 CPU cores, each thread processes a quarter of the primary keys (primary_key & 0x03). This description is, of course, somewhat simplified, but it should get you an idea on the kind of I/O-operations. Regards, Peter Niemayer _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs