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Date: Sat, 11 Mar 2017 06:09:47 -0800
From: Matthew Wilcox <willy@infradead.org>
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Subject: Re: [Qemu-devel] [PATCH v7 kernel 3/5] virtio-balloon:
 implementation of VIRTIO_BALLOON_F_CHUNK_TRANSFER
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To: Wei Wang <wei.w.wang@intel.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>, 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, Liang Li <liang.z.li@intel.com>, Paolo Bonzini <pbonzini@redhat.com>, Cornelia Huck <cornelia.huck@de.ibm.com>, Amit Shah <amit.shah@redhat.com>, Dave Hansen <dave.hansen@intel.com>, Andrea Arcangeli <aarcange@redhat.com>, David Hildenbrand <david@redhat.com>, Liang Li <liliang324@gmail.com>

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)?

Is that a likely thing for the guest to need to do though?  Freeing a
1GB page is much more liikely, IMO.