From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38413) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fihbB-0002y8-O1 for qemu-devel@nongnu.org; Thu, 26 Jul 2018 10:50:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fihbA-0003b3-Og for qemu-devel@nongnu.org; Thu, 26 Jul 2018 10:50:37 -0400 References: <20180724200343.13733-1-lbloch@janustech.com> <20180724200343.13733-4-lbloch@janustech.com> <20180725082611.GA4879@localhost.localdomain> <32a32b18-0c7c-63cd-3b1d-429717b23a85@redhat.com> <499d5d12-cdba-76e4-3b2e-122675ef9eec@janustech.com> <20180725133243.GC4879@localhost.localdomain> <20180725155323.GD4879@localhost.localdomain> <0638cd7c-23f7-0f99-735b-c3fb3102e254@janustech.com> <20180726144232.GE4215@localhost.localdomain> From: Leonid Bloch Message-ID: Date: Thu, 26 Jul 2018 17:50:15 +0300 MIME-Version: 1.0 In-Reply-To: <20180726144232.GE4215@localhost.localdomain> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB-large Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v3 3/5] qcow2: Introduce an option for sufficient L2 cache for the entire image List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: Eric Blake , qemu-devel@nongnu.org, qemu-block@nongnu.org, Max Reitz On 07/26/2018 05:42 PM, Kevin Wolf wrote: > Am 26.07.2018 um 14:24 hat Leonid Bloch geschrieben: >>>> You mean with QDict? I'll look into that now. But already sent v5 before >>>> reading this email. >>> >>> Yes, with reading it from the QDict. (Or whatever the simplest way is >>> that results in the right external interface, but I suppose this is the >>> one.) >> >> Well, there is a problem with that: I can easily isolate >> l2-cache-size from QDict, check if it is "full", and if it is - do whatever >> is needed, and delete this option before parsing. But what if it is "foo"? >> It will not get deleted, and the regular QEMU_OPT_SIZE parsing error will >> appear, stating that l2-cache-size "expects a non-negative number..." - no >> word about that it can expect "full" as well. Now, one can try to modify >> local_err->msg for this particular option, but this will require substantial >> additional logic. I think considering this, it would be easier to stick with >> a dedicated option, l2-cache-full. >> >> Do you think there is a smarter way to parse the l2-cache-size option, so it >> would accept both size and "full", while handling errors correctly? It seems >> more elegant to have a single option, but the internal handling will be more >> elegant and simpler with two mutually exclusive options. > > I think we can live with the suboptimal error message for a while. Once > qcow2 is QAPIfied, it should become easy to improve it. Let's not choose > a worse design (that stays forever) for a temporarily better error > message. OK. I'll add a TODO then. > >> By the way, the L2 cache resizes now on image resize. Will send the changes >> in v6. Thanks for the suggestion! > > Sounds good! > > Kevin >