From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754065Ab2CROCD (ORCPT ); Sun, 18 Mar 2012 10:02:03 -0400 Received: from einhorn.in-berlin.de ([192.109.42.8]:37225 "EHLO einhorn.in-berlin.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752930Ab2CROCB (ORCPT ); Sun, 18 Mar 2012 10:02:01 -0400 X-Envelope-From: stefanr@s5r6.in-berlin.de Date: Sun, 18 Mar 2012 15:01:27 +0100 From: Stefan Richter To: Wakko Warner Cc: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org Subject: Re: Burning multiple DVDs at one time Message-ID: <20120318150127.5f8db40c@stein> In-Reply-To: <20120318133059.GB10172@animx.eu.org> References: <20120315225310.GB3152@animx.eu.org> <20120317095644.145d0588@stein> <20120317142255.GB26403@animx.eu.org> <20120317162853.13afa28b@stein> <20120318133059.GB10172@animx.eu.org> X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.8; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mar 18 Wakko Warner wrote: > Stefan Richter wrote: > > On Mar 17 Wakko Warner wrote: > > > Thanks. I looked at the patch. I would just like to confirm that I can > > > patch my 3.0.0 vanilla kernel, compile the sr module, unload the current and > > > load the patched one without the need to reboot. > > > > Yes, this should be possible. > > > > Oh, I only noticed just know that you also wrote: > > > > > > > The kernel is a vanilla kernel v3.0.0. (This also happened with 2.6.35) > > > > In 2.6.35, the Big Kernel Lock was still in place there. That lock > > behaved differently from a plain mutex --- notably it was released when a > > thread went to sleep --- so maybe there is more to your problem than just > > sr_mutex blocking unrelated sr accesses. > > There is a good possibility that I was mistaken on the 2.6.35. > > I manually applied your patch to 3.0.0, compiled, removed sr-mod module and > inserted the newly compiled one. > > With the vanilla one, I would see the buf % in wodim drop while the fifo was > full. With the patch (removing the mutex), buf stayed above 98% and the > burn speed was 16x at the end (10x avg). > > Seems to have fixed my problem. Very nice; so there is an almost easy fix. Now I or somebody else need to work out the required cdrom_device_info protection on which Arnd and James commented. -- Stefan Richter -=====-===-- --== =--=- http://arcgraph.de/sr/