From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=34809 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PmjWV-0004Gf-8M for qemu-devel@nongnu.org; Tue, 08 Feb 2011 04:06:12 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PmjWT-0001Na-3W for qemu-devel@nongnu.org; Tue, 08 Feb 2011 04:06:11 -0500 Received: from hall.aurel32.net ([88.191.126.93]:51687) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PmjWS-0001Mu-Sl for qemu-devel@nongnu.org; Tue, 08 Feb 2011 04:06:09 -0500 Message-ID: <4D510771.3040309@aurel32.net> Date: Tue, 08 Feb 2011 10:05:53 +0100 From: Aurelien Jarno MIME-Version: 1.0 References: <4D3DFD20.8060004@linux.vnet.ibm.com> <20110125091741.GB30239@edde.se.axis.com> <20110125133453.GC5427@amt.cnet> <20110207101255.GA20413@amt.cnet> <20110207160350.GA26332@amt.cnet> <4D501C71.7090708@redhat.com> <4D50279B.5010102@siemens.com> <4D505DCB.9050406@codemonkey.ws> <20110207214551.GB16429@hall.aurel32.net> <4D50A5F0.802@codemonkey.ws> <20110208072657.GD16429@hall.aurel32.net> <4D50FA14.5010100@redhat.com> <4D5103E8.6050808@siemens.com> In-Reply-To: <4D5103E8.6050808@siemens.com> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] Re: [PATCH 2/7] Enable I/O thread and VNC threads by default List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: Anthony Liguori , Stefan Hajnoczi , Marcelo Tosatti , "qemu-devel@nongnu.org" , Anthony Liguori , Paul Brook , "Edgar E. Iglesias" , Paolo Bonzini , Arun Bharadwaj Jan Kiszka a écrit : > On 2011-02-08 09:08, Paolo Bonzini wrote: >> On 02/08/2011 08:26 AM, Aurelien Jarno wrote: >>> I forget to remember when we decided that AIO should be implemented on >>> any host OS. Any pointer? >> To be fair, I/O-heavy workloads are almost unusable without AIO. For >> Window targets, they also crash under SMP due to the Windows AP >> watchdog. But then TCG and SMP do not go very well together anyway. >> >> However, I think deprecating Win32 support would be a very bad idea. > > It would be too early at this point. > > But if Windows is once the only reason to keep tons of hardly tested > code paths around or to invest significant additional effort to change > logic or interfaces in this area, than I would prefer that step. I'm > hacking on IOTHREAD vs. !IOTHREAD for some weeks now, and all those > subtle differences are really a PITA and source of various breakages. > > People interested in that platform should finally realize that its fate > is coupled to reducing the #ifdefs as well as the design differences we > see right now and even more in the future. > The guilty here is IOTHREAD. Windows support predates IOTHREAD concept, it's just that people who introduce IOTHREAD didn't care about Windows support at all and added these #ifdef. Disabling Windows support because of that is not fair. We should probably get rid of KVM support in QEMU, so if someone has an idea for a cool TCG feature that can't be supported in KVM, it's the moment to submit it. We can add it with #ifdef, and in one year just ask for KVM support removal. -- Aurelien Jarno GPG: 1024D/F1BCDB73 aurelien@aurel32.net http://www.aurel32.net