From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bartlomiej Zolnierkiewicz Subject: Re: [PATCH] ide-cd: remove the internal 64k buffer Date: Tue, 19 Feb 2008 22:51:36 +0100 Message-ID: <200802192251.37183.bzolnier@gmail.com> References: <20080219143247.GA3980@gollum.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from nf-out-0910.google.com ([64.233.182.187]:1817 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761812AbYBSWD7 (ORCPT ); Tue, 19 Feb 2008 17:03:59 -0500 Received: by nf-out-0910.google.com with SMTP id g13so756837nfb.21 for ; Tue, 19 Feb 2008 14:03:59 -0800 (PST) In-Reply-To: <20080219143247.GA3980@gollum.tnic> Content-Disposition: inline Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: petkovbb@gmail.com Cc: linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org Hi, On Tuesday 19 February 2008, Borislav Petkov wrote: > Hi Bart, > > here's one more item from my TODO list. The removal is straight forward, after > testing it with all my cdrom drives they all seem even to rotate quieter due to > the automatic speed adjustment of the drive to the continuous data stream > bandwidth in contrast to the buffer-mode in which recurring buffer-fill speedups > caused the drive's read speeed to spike in order to keep the buffer filled up > constantly. > > Still, i'd keep this a bit longer in -mm to see whether there are some > other issues with it and with all the different workloads. > > > commit a855bd5d94ddac678cf90b4b8f20dbd3ac8ea29a > Author: Borislav Petkov > Date: Tue Feb 19 14:25:09 2008 +0100 > > ide-cd: remove the internal 64k buffer > > This removes the internal ide-cd buffer and falls back to read-ahead block layer > capabilities. Thorough testing (cd burning, dvd read, raw read) gives with the > bufferless mode marginally better performance in addition to simplified code. > > bufferless: > > dd: reading `/dev/hdc': Input/output error > 6238+0 records in > 6238+0 records out > 204406784 bytes (204 MB) copied, 259.891 s, 787 kB/s > > real 4m21.598s > user 0m0.014s > sys 0m0.744s > > with the old buffer (2.6.25-rc1): > > dd: reading `/dev/hdc': Input/output error > 6238+0 records in > 6238+0 records out > 204406784 bytes (204 MB) copied, 262.893 s, 778 kB/s > > real 4m22.938s > user 0m0.009s > sys 0m0.771s > > Signed-off-by: Borislav Petkov applied, thanks