From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=56696 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OE38y-0008Mt-Fw for qemu-devel@nongnu.org; Mon, 17 May 2010 12:26:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OE38w-00057r-LH for qemu-devel@nongnu.org; Mon, 17 May 2010 12:26:16 -0400 Received: from mail-vw0-f45.google.com ([209.85.212.45]:39697) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OE38w-00057l-Hr for qemu-devel@nongnu.org; Mon, 17 May 2010 12:26:14 -0400 Received: by vws1 with SMTP id 1so955288vws.4 for ; Mon, 17 May 2010 09:26:13 -0700 (PDT) Message-ID: <4BF16E22.6090400@codemonkey.ws> Date: Mon, 17 May 2010 11:26:10 -0500 From: Anthony Liguori MIME-Version: 1.0 Subject: Re: [Qemu-devel] Re: [PATCH] Add cache=volatile parameter to -drive References: <1274091292-4812-1-git-send-email-agraf@suse.de> <4BF14CE9.5040907@suse.de> <4BF15DC8.8080104@codemonkey.ws> <201005171723.15675.paul@codesourcery.com> In-Reply-To: <201005171723.15675.paul@codesourcery.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paul Brook Cc: kwolf@redhat.com, hch@lst.de, qemu-devel@nongnu.org, Alexander Graf On 05/17/2010 11:23 AM, Paul Brook wrote: >>> I don't see a difference between the results. Apparently the barrier >>> option doesn't change a thing. >>> >> Ok. I don't like it, but I can see how it's compelling. I'd like to >> see the documentation improved though. I also think a warning printed >> on stdio about the safety of the option would be appropriate. >> > I disagree with this last bit. > > Errors should be issued if the user did something wrong. > Warnings should be issued if qemu did (or will soon do) something other than > what the user requested, or otherwise made questionable decisions on the > user's behalf. > > In this case we're doing exactly what the user requested. The only plausible > failure case is where a user is blindly trying options that they clearly don't > understand or read the documentation for. I have zero sympathy for complaints > like "Someone on the Internet told me to use --breakme, and broke thinks". > I see it as the equivalent to the Taint bit in Linux. I want to make it clear to users up front that if you use this option, and you have data loss issues, don't complain. Just putting something in qemu-doc.texi is not enough IMHO. Few people actually read it. Regards, Anthony Liguori > Paul > >