From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bartlomiej Zolnierkiewicz Subject: Re: [git patches] IDE update Date: Mon, 4 Jul 2005 22:47:39 +0200 Message-ID: <58cb370e05070413472629dd58@mail.gmail.com> References: <58cb370e0507041251dd5a@mail.gmail.com> <200507042033.XAA19724@raad.intranet> Reply-To: Bartlomiej Zolnierkiewicz Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: Received: from nproxy.gmail.com ([64.233.182.206]:48454 "EHLO nproxy.gmail.com") by vger.kernel.org with ESMTP id S261658AbVGDUrm convert rfc822-to-8bit (ORCPT ); Mon, 4 Jul 2005 16:47:42 -0400 Received: by nproxy.gmail.com with SMTP id o25so183965nfa for ; Mon, 04 Jul 2005 13:47:39 -0700 (PDT) In-Reply-To: <200507042033.XAA19724@raad.intranet> Content-Disposition: inline Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Al Boldi Cc: Ondrej Zary , Linus Torvalds , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org On 7/4/05, Al Boldi wrote: > Bartlomiej Zolnierkiewicz wrote: { > > > > > >>On 7/4/05, Al Boldi wrote: > > >>Hdparm -tT gives 38mb/s in 2.4.31 > > >>Cat /dev/hda > /dev/null gives 2% user 33% sys 65% idle > > >> > > >>Hdparm -tT gives 28mb/s in 2.6.12 > > >>Cat /dev/hda > /dev/null gives 2% user 25% sys 0% idle 73% IOWAIT > > >> > > >>It feels like DMA is not being applied properly in 2.6.12. > > > > > > Same on 2.6.10,11,12. > > > No errors though, only sluggish system. > > What about earlier kernels? > Please try to narrow down the problem to a specific kernel version. > } > > Don't know about 2.6.0-2.6.9, but 2.4.31 is ok. 2.4 -> 2.6 means zillions of changes. > Bartlomiej, > When you compare 2.4.31 with 2.6.12 don't you see this problem on your > machine? Unfortunately I've never encountered this problem on any machine. > If you have a fast system the slowdown won't show, but your IOWAIT will be > higher anyway! AFAIK high iowait is a known block layer problem > It feels like running on PIO instead of DMA.