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, 26 Oct 2001 07:48:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 26 Oct 2001 07:47:59 -0400 Received: from penguin.e-mind.com ([195.223.140.120]:3155 "EHLO penguin.e-mind.com") by vger.kernel.org with ESMTP id ; Fri, 26 Oct 2001 07:47:44 -0400 Date: Fri, 26 Oct 2001 13:48:19 +0200 From: Andrea Arcangeli To: Marvin Justice Cc: linux-kernel@vger.kernel.org Subject: Re: 2.4.13-pre5-aa1 O_DIRECT drastic HIGHMEM performance hit Message-ID: <20011026134819.D30905@athlon.random> In-Reply-To: <3B6867E6CB09B24385A73719A50C7C9A01797E@athena.boxxtech.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.12i In-Reply-To: <3B6867E6CB09B24385A73719A50C7C9A01797E@athena.boxxtech.com>; from Mjustice@boxxtech.com on Thu, Oct 25, 2001 at 11:57:08AM -0500 X-GnuPG-Key-URL: http://e-mind.com/~andrea/aa.gnupg.asc X-PGP-Key-URL: http://e-mind.com/~andrea/aa.asc Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 25, 2001 at 11:57:08AM -0500, Marvin Justice wrote: > Are we stuck with a low mem configuration or are there workarounds that > would allow us to stick with the initial 2GB of RAM and still get ~200 > MB/sec. the problem you seen isn't specific to O_DIRECT. This should solve your problem (not just for O_DIRECT): ftp://ftp.us.kernel.org/pub/linux/kernel/people/people/axboe/patches/2.4.13-pre4/block-highmem-all-17.bz2 It's a long time that I want to include the anti-bounce bits, but I am still looking into the vm. The uglier part is that I suspect we'll also need to make a 2G bounce option for some hardware combination. I hope I'm wrong :). Andrea