From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f71.google.com (mail-pg0-f71.google.com [74.125.83.71]) by kanga.kvack.org (Postfix) with ESMTP id CBC6C6B000A for ; Fri, 15 Jun 2018 10:28:53 -0400 (EDT) Received: by mail-pg0-f71.google.com with SMTP id o19-v6so3452172pgn.14 for ; Fri, 15 Jun 2018 07:28:53 -0700 (PDT) Received: from mga07.intel.com (mga07.intel.com. [134.134.136.100]) by mx.google.com with ESMTPS id e9-v6si9156915pli.337.2018.06.15.07.28.52 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 15 Jun 2018 07:28:52 -0700 (PDT) From: "Wang, Wei W" Subject: RE: [PATCH v33 0/4] Virtio-balloon: support free page reporting Date: Fri, 15 Jun 2018 14:28:49 +0000 Message-ID: <286AC319A985734F985F78AFA26841F7396A3DC9@shsmsx102.ccr.corp.intel.com> References: <1529037793-35521-1-git-send-email-wei.w.wang@intel.com> <20180615142610-mutt-send-email-mst@kernel.org> In-Reply-To: <20180615142610-mutt-send-email-mst@kernel.org> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: "Michael S. Tsirkin" 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" 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 f= ree > > page hint command to the guest (via the host_cmd config registe= r) > > to start the reporting. >=20 > 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 agai= n. 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 h= int by hint as before. And the guest notifies host after the buffer is deli= vered. In any case, the host doorbell handler will be invoked, if host does= n't need the hints at that time, it will just give back the buffer. There w= ill be no stale hints remained in the ring now. Best, Wei