From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wakko Warner Subject: Re: Burning multiple DVDs at one time Date: Sat, 28 Apr 2012 12:02:27 -0400 Message-ID: <20120428160226.GA9811@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> <20120318150127.5f8db40c@stein> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20120318150127.5f8db40c@stein> Sender: linux-kernel-owner@vger.kernel.org To: Stefan Richter Cc: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org List-Id: linux-scsi@vger.kernel.org Stefan Richter wrote: > 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. Has anything come of this as far as the fix going into the kernel? -- Microsoft has beaten Volkswagen's world record. Volkswagen only created 22 million bugs.