From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by aws-us-west-2-korg-lkml-1.web.codeaurora.org (Postfix) with ESMTP id 0B217C5CFC1 for ; Fri, 15 Jun 2018 14:38:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B76542088E for ; Fri, 15 Jun 2018 14:38:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B76542088E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756264AbeFOOie (ORCPT ); Fri, 15 Jun 2018 10:38:34 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:60558 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756167AbeFOOid (ORCPT ); Fri, 15 Jun 2018 10:38:33 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id ADD7E8A6FA; Fri, 15 Jun 2018 14:38:32 +0000 (UTC) Received: from redhat.com (ovpn-120-46.rdu2.redhat.com [10.10.120.46]) by smtp.corp.redhat.com (Postfix) with SMTP id F3E4520284D6; Fri, 15 Jun 2018 14:38:31 +0000 (UTC) Date: Fri, 15 Jun 2018 17:38:31 +0300 From: "Michael S. Tsirkin" To: "Wang, Wei W" Cc: "virtio-dev@lists.oasis-open.org" , "linux-kernel@vger.kernel.org" , "virtualization@lists.linux-foundation.org" , "kvm@vger.kernel.org" , "linux-mm@kvack.org" , "mhocko@kernel.org" , "akpm@linux-foundation.org" , "torvalds@linux-foundation.org" , "pbonzini@redhat.com" , "liliang.opensource@gmail.com" , "yang.zhang.wz@gmail.com" , "quan.xu0@gmail.com" , "nilal@redhat.com" , "riel@redhat.com" , "peterx@redhat.com" Subject: Re: [PATCH v33 0/4] Virtio-balloon: support free page reporting Message-ID: <20180615172933-mutt-send-email-mst@kernel.org> References: <1529037793-35521-1-git-send-email-wei.w.wang@intel.com> <20180615142610-mutt-send-email-mst@kernel.org> <286AC319A985734F985F78AFA26841F7396A3DC9@shsmsx102.ccr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <286AC319A985734F985F78AFA26841F7396A3DC9@shsmsx102.ccr.corp.intel.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Fri, 15 Jun 2018 14:38:32 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Fri, 15 Jun 2018 14:38:32 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'mst@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 15, 2018 at 02:28:49PM +0000, Wang, Wei W wrote: > On Friday, June 15, 2018 7:30 PM, Michael S. Tsirkin wrote: > > On Fri, Jun 15, 2018 at 12:43:09PM +0800, Wei Wang wrote: > > > - remove the cmd id related interface. Now host can just send a free > > > page hint command to the guest (via the host_cmd config register) > > > to start the reporting. > > > > Here we go again. And what if reporting was already started previously? > > I don't think it's a good idea to tweak the host/guest interface yet again. > > This interface is much simpler, and I'm not sure if that would be an > issue here now, because now the guest delivers the whole buffer of > hints to host once, instead of hint by hint as before. And the guest > notifies host after the buffer is delivered. In any case, the host > doorbell handler will be invoked, if host doesn't need the hints at > that time, it will just give back the buffer. There will be no stale > hints remained in the ring now. > > Best, > Wei I still think all the old arguments for cmd id apply. -- MST