Re: [PATCH 0/2] virtio_balloon: do not change memory amount visible via /proc/meminfo

["Denis V. Lunev" <den@openvz.org>]

On 08/20/2015 12:49 AM, Denis V. Lunev wrote:
> Though there is a problem in this setup. The end-user and hosting provider
> have signed SLA agreement in which some amount of memory is guaranted for
> the guest. The good thing is that this memory will be given to the guest
> when the guest will really need it (f.e. with OOM in guest and with
> VIRTIO_BALLOON_F_DEFLATE_ON_OOM configuration flag set). The bad thing
> is that end-user does not know this.
>
> Balloon by default reduce the amount of memory exposed to the end-user
> each time when the page is stolen from guest or returned back by using
> adjust_managed_page_count and thus /proc/meminfo shows reduced amount
> of memory.
>
> Fortunately the solution is simple, we should just avoid to call
> adjust_managed_page_count with VIRTIO_BALLOON_F_DEFLATE_ON_OOM set.
>
> Please note that neither VMWare ballon nor HyperV balloon do not care
> about proper handling of adjust_managed_page_count at all.
>
> Signed-off-by: Denis V. Lunev <den@openvz.org>
> CC: Michael S. Tsirkin <mst@redhat.com>
ping

Michael, the issue is important for us. Can you pls look?

Den