Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261417AbVDUPGM (ORCPT ); Thu, 21 Apr 2005 11:06:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261422AbVDUPGM (ORCPT ); Thu, 21 Apr 2005 11:06:12 -0400 Received: from palrel11.hp.com ([156.153.255.246]:44700 "EHLO palrel11.hp.com") by vger.kernel.org with ESMTP id S261417AbVDUPF4 (ORCPT ); Thu, 21 Apr 2005 11:05:56 -0400 From: David Mosberger MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16999.49458.498919.807191@napali.hpl.hp.com> Date: Thu, 21 Apr 2005 08:05:22 -0700 To: tony.luck@intel.com, akpm@osdl.org Cc: Andreas Hirstius , Bartlomiej ZOLNIERKIEWICZ , Gelato technical , linux-kernel@vger.kernel.org Subject: Re: [Gelato-technical] Re: Serious performance degradation on a RAID with kernel 2.6.10-bk7 and later In-Reply-To: <42678EEA.6070109@cern.ch> References: <42669357.9080604@cern.ch> <42668977.5060708@utah-nac.org> <42676501.8030805@cern.ch> <58cb370e05042102272ce70f2@mail.gmail.com> <42677587.8030707@cern.ch> <42678EEA.6070109@cern.ch> X-Mailer: VM 7.19 under Emacs 21.4.1 Reply-To: davidm@hpl.hp.com X-URL: http://www.hpl.hp.com/personal/David_Mosberger/ Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1582 Lines: 53 Tony and Andrew, I just checked 2.6.12-rc3 and the fls() fix is indeed missing. Do you know what happened? --david >>>>> On Thu, 21 Apr 2005 13:30:50 +0200, Andreas Hirstius said: Andreas> Hi, The fls() patch from David solves the problem :-)) Andreas> Do you have an idea, when it will be in the mainline Andreas> kernel?? Andreas> Andreas Andreas> Bartlomiej ZOLNIERKIEWICZ wrote: >> Hi! >> >>> A small update. >>> >>> Patching mm/filemap.c is not necessary in order to get the >>> improved performance! It's sufficient to remove >>> roundup_pow_of_two from |get_init_ra_size ... >>> >>> So a simple one-liner changes to picture dramatically. But why >>> ?!?!? >> >> >> roundup_pow_of_two() uses fls() and ia64 has buggy fls() >> implementation [ seems that David fixed it but patch is not in >> the mainline yet]: >> >> http://www.mail-archive.com/linux-ia64@vger.kernel.org/msg01196.html >> >> That would also explain why you couldn't reproduce the problem on >> ia32 Xeon machines. >> >> Bartlomiej >> Andreas> _______________________________________________ Andreas> Gelato-technical mailing list Andreas> Gelato-technical@gelato.unsw.edu.au Andreas> https://www.gelato.unsw.edu.au/mailman/listinfo/gelato-technical - 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/