From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:51040) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UQKNO-0007Og-0a for qemu-devel@nongnu.org; Thu, 11 Apr 2013 12:29:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UQKNL-0002dF-4a for qemu-devel@nongnu.org; Thu, 11 Apr 2013 12:29:29 -0400 Received: from e39.co.us.ibm.com ([32.97.110.160]:54298) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UQKNK-0002d5-M0 for qemu-devel@nongnu.org; Thu, 11 Apr 2013 12:29:27 -0400 Received: from /spool/local by e39.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 11 Apr 2013 10:29:25 -0600 Received: from d03relay01.boulder.ibm.com (d03relay01.boulder.ibm.com [9.17.195.226]) by d03dlp01.boulder.ibm.com (Postfix) with ESMTP id 94BF31FF004C for ; Thu, 11 Apr 2013 10:24:21 -0600 (MDT) Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by d03relay01.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r3BGTE6P115178 for ; Thu, 11 Apr 2013 10:29:15 -0600 Received: from d03av01.boulder.ibm.com (loopback [127.0.0.1]) by d03av01.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r3BGTBKc024185 for ; Thu, 11 Apr 2013 10:29:12 -0600 Message-ID: <5166E4CC.2020205@linux.vnet.ibm.com> Date: Thu, 11 Apr 2013 12:29:00 -0400 From: "Michael R. Hines" MIME-Version: 1.0 References: <1365632901-15470-1-git-send-email-mrhines@linux.vnet.ibm.com> <1365632901-15470-11-git-send-email-mrhines@linux.vnet.ibm.com> <20130411073843.GB19601@redhat.com> <51667FEE.903@redhat.com> <5166B9A9.9070904@linux.vnet.ibm.com> <5166C59A.4010904@redhat.com> <5166CF56.2060105@linux.vnet.ibm.com> <5166D1DA.3050804@redhat.com> <5166D826.207@linux.vnet.ibm.com> <5166DAA0.1010507@redhat.com> <5166DFBC.8010805@redhat.com> In-Reply-To: <5166DFBC.8010805@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH RDMA support v1: 10/13] introduce new command migrate_check_for_zero List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake Cc: aliguori@us.ibm.com, "Michael S. Tsirkin" , qemu-devel@nongnu.org, owasserm@redhat.com, abali@us.ibm.com, mrhines@us.ibm.com, gokul@us.ibm.com, Paolo Bonzini On 04/11/2013 12:07 PM, Eric Blake wrote: > On 04/11/2013 09:45 AM, Paolo Bonzini wrote: >> Il 11/04/2013 17:35, Michael R. Hines ha scritto: >>> Nevertheless, the initial "burst" of the bulk phase round is still >>> important to optimize, and I would like to know if the maintainer >>> would accept this API for disabling the scan or not >> I'm not a maintainer, but every opinion counts... and my opinion is "not >> yet". Maybe for 1.6, and only after someone else tried it out. That's >> why it's important to merge the code early. > Agreed on that point - it's always easier to add an interface later, > when we have field usage suggesting that it would be useful, than it is > to remove an interface once provided, but where field usage says it is > never tweaked from the default. > > Having a knob for disabling zero detection might make sense in the > future, but no need to rush it into 1.5 and regret the design, and no > need to hold up getting RDMA into 1.5 just because of a debate about a > knob that can be deferred to a later release when we've had more time to > play with RDMA. > Agreed, so what about my second proposal? Disabling zero detection "on demand" if and only if RDMA is enabled and if and only if chunk registration is disabled? - Michael