From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tim Small Subject: Re: [PATCH 0/4] Fix performance burning or extracting audio etc. from multiple optical drives. Date: Thu, 05 Nov 2015 09:36:32 +0000 Message-ID: <563B2320.9070106@seoss.co.uk> References: <20141121100210.GC8866@infradead.org> <1416924562-16849-1-git-send-email-tim@seoss.co.uk> <20151105013806.GA21819@animx.eu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: Received: from relay1.allsecuredomains.com ([78.47.251.4]:34204 "EHLO relay1.allsecuredomains.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030570AbbKEKNp (ORCPT ); Thu, 5 Nov 2015 05:13:45 -0500 In-Reply-To: <20151105013806.GA21819@animx.eu.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Wakko Warner Cc: tim@buttersideup.com, Christoph Hellwig , linux-scsi@vger.kernel.org, Jens Axboe , Borislav Petkov , Tim Waugh On 05/11/15 01:38, Wakko Warner wrote: > I tested on a system with 3 drives. ejecting all drives didn't happen at > the same time, but I think it's because they are different brands and one > didn't have a disc in. I did notice the leds coming on about the same time > though. eject -t on all drives happened at the same time. > > The patch I used previously on 3.3.0 removed all mutex_lock and mutex_unlock > lines from sr.c where as this patchset didn't. I plan on trying to burn 3 > dvds to see if it works. > > Thanks for your work on the patches. No problem. I haven't had any time to follow up (and probably won't for the foreseeable - I've got far too much on at the moment unfortunately), and the locking issues looked non-trivial unfortunately. In my testing burning, and audio extracting etc. worked pretty flawlessly IIRC, it was just the eject/load path which seemed to have locking issues. The test was just a shell scripts which ran: while true ; do eject /dev/sr0 ; eject -T /dev/sr0 ; done for every drive in the system simultaneously. Hopefully it's a good start if someone wants to pick it up. It's possible that there's an easy way of leaving the old mutexes (or adding more) around the relevant open/eject/load paths only, but I can't remember the code now unfortunately. If anyone wants to have a go, I think I can probably rig up about 8 drives to a testrig here, and will be happy to give it a test. Tim.