From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id 51C5B28094A for ; Sat, 11 Mar 2017 20:59:59 -0500 (EST) Received: by mail-pf0-f198.google.com with SMTP id v190so235611651pfb.5 for ; Sat, 11 Mar 2017 17:59:59 -0800 (PST) Received: from mga02.intel.com (mga02.intel.com. [134.134.136.20]) by mx.google.com with ESMTPS id t8si7558881pgo.353.2017.03.11.17.59.58 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 11 Mar 2017 17:59:58 -0800 (PST) From: "Wang, Wei W" Subject: RE: [PATCH v7 kernel 3/5] virtio-balloon: implementation of VIRTIO_BALLOON_F_CHUNK_TRANSFER Date: Sun, 12 Mar 2017 01:59:54 +0000 Message-ID: <286AC319A985734F985F78AFA26841F73919E524@shsmsx102.ccr.corp.intel.com> References: <1488519630-89058-1-git-send-email-wei.w.wang@intel.com> <1488519630-89058-4-git-send-email-wei.w.wang@intel.com> <20170309141411.GZ16328@bombadil.infradead.org> <58C28FF8.5040403@intel.com> <20170310175349-mutt-send-email-mst@kernel.org> <20170310171143.GA16328@bombadil.infradead.org> <58C3E6A3.1000000@intel.com> <20170311140946.GA1860@bombadil.infradead.org> In-Reply-To: <20170311140946.GA1860@bombadil.infradead.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: Matthew Wilcox Cc: "Michael S. Tsirkin" , "virtio-dev@lists.oasis-open.org" , "kvm@vger.kernel.org" , "qemu-devel@nongnu.org" , "linux-kernel@vger.kernel.org" , "virtualization@lists.linux-foundation.org" , "linux-mm@kvack.org" , Paolo Bonzini , Cornelia Huck , Amit Shah , "Hansen, Dave" , Andrea Arcangeli , David Hildenbrand , Liang Li On 03/11/2017 10:10 PM, Matthew Wilcox wrote: > On Sat, Mar 11, 2017 at 07:59:31PM +0800, Wei Wang wrote: > > I'm thinking what if the guest needs to transfer these much physically > > continuous memory to host: 1GB+2MB+64KB+32KB+16KB+4KB. > > Is it going to use Six 64-bit chunks? Would it be simpler if we just > > use the 128-bit chunk format (we can drop the previous normal 64-bit > > format)? >=20 > Is that a likely thing for the guest to need to do though? Freeing a 1GB= page is > much more liikely, IMO. Yes, I think it's very possible. The host can ask for any number of pages (= e.g. 1.5GB) that the guest can afford. Also, the ballooned 1.5G memory is = not guaranteed to be continuous in any pattern like 1GB+512MB. That's why w= e need to use a bitmap to draw the whole picture first, and then seek for c= ontinuous bits to chunk. Best, Wei -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org