From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sfi-mx-4.v28.ch3.sourceforge.com ([172.29.28.124] helo=mx.sourceforge.net) by h25xhf1.ch3.sourceforge.com with esmtp (Exim 4.69) (envelope-from ) id 1KsexL-0007p3-MB for user-mode-linux-devel@lists.sourceforge.net; Wed, 22 Oct 2008 14:45:03 +0000 Received: from jaguar.ecp.fr ([138.195.33.9]) by 1b2kzd1.ch3.sourceforge.com with esmtp (Exim 4.69) id 1KsexF-0007U9-Ow for user-mode-linux-devel@lists.sourceforge.net; Wed, 22 Oct 2008 14:45:03 +0000 Received: from localhost (localhost [127.0.0.1]) by jaguar.ecp.fr (Postfix) with ESMTP id 6B66968010 for ; Wed, 22 Oct 2008 16:44:55 +0200 (CEST) Received: from jaguar.ecp.fr ([127.0.0.1]) by localhost (jaguar [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 24602-08 for ; Wed, 22 Oct 2008 16:44:55 +0200 (CEST) Received: from [138.195.30.9] (kheops.system.ecp.fr [138.195.30.9]) by jaguar.ecp.fr (Postfix) with ESMTP id 4BD0A68002 for ; Wed, 22 Oct 2008 16:44:55 +0200 (CEST) Message-ID: <48FF3C66.20509@ecp.fr> Date: Wed, 22 Oct 2008 16:44:54 +0200 From: Nicolas Boullis MIME-Version: 1.0 Subject: [uml-devel] I/O Performance List-Id: The user-mode Linux development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: user-mode-linux-devel-bounces@lists.sourceforge.net To: user-mode-linux-devel@lists.sourceforge.net Hi, Sorry for insisting, but I think it would be nice if things could be improved before linux 2.6.28. When COW is not used, the performance is very bad because multiples I/O are performed when one would be enough. Steve VanDeBogart's "ubd does multiple io's when one will suffice" patch look clean and solves the problem. Performing parallel I/O also much improves the performance (at least with ubd=sync), but my patch is certainly not clean enough for inclusion. Jeff, you told me you had such a patch; would you like me tou give it a try? Cheers, Nicolas Boullis ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel