From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:38362) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TDuQV-0002AG-Uk for qemu-devel@nongnu.org; Tue, 18 Sep 2012 05:49:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TDuQQ-0005vU-35 for qemu-devel@nongnu.org; Tue, 18 Sep 2012 05:49:07 -0400 Received: from mail-pb0-f45.google.com ([209.85.160.45]:61634) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TDuQP-0005vP-SV for qemu-devel@nongnu.org; Tue, 18 Sep 2012 05:49:02 -0400 Received: by pbbrp12 with SMTP id rp12so11322372pbb.4 for ; Tue, 18 Sep 2012 02:49:00 -0700 (PDT) Sender: Paolo Bonzini Message-ID: <50584385.7060709@redhat.com> Date: Tue, 18 Sep 2012 11:48:53 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <539633110.1300350.1347959367353.JavaMail.root@redhat.com> <50584184.5080602@redhat.com> In-Reply-To: <50584184.5080602@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] ping Re: [RFC PATCH 00/13] Embedded NBD server List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: stefanha@gmail.com, qemu-devel@nongnu.org, Markus Armbruster Il 18/09/2012 11:40, Kevin Wolf ha scritto: >>> >> Note that after completing the refactoring, we'll only have one combined >>> >> bdrv_close/delete function and so there won't be BlockDriverStates >>> >> that are closed. In this case, I think it's quite obvious that not closing >>> >> the filters wouldn't make any sense. >> > >> > Does that mean that any I/O throttling must be applied again on every >> > medium change? That would be a behavioral change. > Hm, I guess so, at least on the lowest level. The only thing I know for > certain is that maintaining compatibility for the old commands will be > fun, but if possible at all we shouldn't let that compromise our design. Yeah, originally we had the idea of a "proxy" driver where you could stack all your persistent filters. The proxy driver would be needed of course for removable media, but it could also subsume things like bdrv_swap and bdrv_append. Paolo