From mboxrd@z Thu Jan  1 00:00:00 1970
From: Wei Wang <wei.w.wang@intel.com>
Subject: Re: [PATCH v12 5/8] virtio-balloon: VIRTIO_BALLOON_F_SG
Date: Mon, 31 Jul 2017 20:36:09 +0800
Message-ID: <597F2439.5070309@intel.com>
References: <59686EEB.8080805@intel.com> <20170723044036-mutt-send-email-mst@kernel.org> <59781119.8010200@intel.com> <20170726155856-mutt-send-email-mst@kernel.org> <597954E3.2070801@intel.com> <20170729020231-mutt-send-email-mst@kernel.org> <597C83CC.7060702@intel.com> <20170730043922-mutt-send-email-mst@kernel.org> <286AC319A985734F985F78AFA26841F739288D85@shsmsx102.ccr.corp.intel.com> <20170730191735-mutt-send-email-mst@kernel.org> <20170730191911-mutt-send-email-mst@kernel.org>
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To: "Michael S. Tsirkin" <mst@redhat.com>
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On 07/31/2017 12:20 AM, Michael S. Tsirkin wrote:
> On Sun, Jul 30, 2017 at 07:18:33PM +0300, Michael S. Tsirkin wrote:
>> On Sun, Jul 30, 2017 at 05:59:17AM +0000, Wang, Wei W wrote:
>> That's a hypervisor implementation detail. From guest point of view,
>> discarding contents can not be distinguished from writing old contents.
>>
> Besides, ignoring the free page tricks, consider regular ballooning.
> We map page with DONTNEED then back with WILLNEED. Result is
> getting a zero page. So at least one of deflate/inflate should be input.
> I'd say both for symmetry.
>

OK, I see the point. Thanks.

Best,
Wei

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