From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: On guest free page hinting and OOM
Date: Thu, 4 Apr 2019 09:28:38 -0400
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Cc: David Hildenbrand <david@redhat.com>,
        Nitesh Narayan Lal <nitesh@redhat.com>,
        kvm list <kvm@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-mm <linux-mm@kvack.org>,
        Paolo Bonzini <pbonzini@redhat.com>, lcapitulino@redhat.com,
        pagupta@redhat.com, wei.w.wang@intel.com,
        Yang Zhang <yang.zhang.wz@gmail.com>,
        Rik van Riel <riel@surriel.com>, dodgen@google.com,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
        dhildenb@redhat.com, Andrea Arcangeli <aarcange@redhat.com>
To: Alexander Duyck <alexander.duyck@gmail.com>
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On Tue, Apr 02, 2019 at 04:43:03PM -0700, Alexander Duyck wrote:
> Yes, but hopefully it should be a small enough amount that nobody will
> notice. In many cases devices such as NICs can consume much more than
> this regularly for just their Rx buffers and it is not an issue. There
> has to be a certain amount of overhead that any given device is
> allowed to consume. If we contain the balloon hinting to just 64M that
> should be a small enough amount that nobody would notice in practice.

I am still inclined to add ability for balloon to exit to host on OOM
if any hints are outstanding.

If nothing else will be helpful for stats.

-- 
MST