Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759126Ab0HES7F (ORCPT ); Thu, 5 Aug 2010 14:59:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36625 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758080Ab0HES7C (ORCPT ); Thu, 5 Aug 2010 14:59:02 -0400 From: Jeff Moyer To: Chris Mason Cc: Dominik Brodowski , Valdis.Kletnieks@vt.edu, josef@redhat.com, Michael Monnerie , Christoph Hellwig , linux-raid@vger.kernel.org, xfs@oss.sgi.com, linux-kernel@vger.kernel.org, dm-devel@redhat.com Subject: Re: direct-io regression [Was: How to track down abysmal performance ata - raid1 - crypto - vg/lv - xfs] References: <20100804073546.GA7494@comet.dominikbrodowski.net> <20100804085039.GA11671@infradead.org> <20100804091317.GA27779@isilmar-3.linta.de> <20100804092122.GA2998@infradead.org> <20100804073546.GA7494@comet.dominikbrodowski.net> <201008041116.09822@zmi.at> <20100804102526.GB13766@isilmar-3.linta.de> <15446.1280953986@localhost> <20100805093100.GA3001@comet.dominikbrodowski.net> <20100805113240.GA29846@think> X-PGP-KeyID: 1F78E1B4 X-PGP-CertKey: F6FE 280D 8293 F72C 65FD 5A58 1FF8 A7CA 1F78 E1B4 X-PCLoadLetter: What the f**k does that mean? Date: Thu, 05 Aug 2010 14:58:37 -0400 In-Reply-To: <20100805113240.GA29846@think> (Chris Mason's message of "Thu, 5 Aug 2010 07:32:40 -0400") Message-ID: User-Agent: Gnus/5.110011 (No Gnus v0.11) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 563 Lines: 16 Chris Mason writes: > But, I'm surprised your drive is doing 8K dio reads at 16MB/s, that > seems a little high. I'm not sure why you think that. We're talking about a plain old SATA disk, right? I can get 40-50MB/s on my systems for 8KB O_DIRECT reads. What am I missing? Cheers, Jeff -- 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/