svn commit: r267858 - in head/sys/dev: virtio/balloon xen/balloon

[Attilio Rao]

On Wed, Jun 25, 2014 at 11:51 AM, Roger Pau Monné <royger at freebsd.org> wrote:
> Author: royger
> Date: Wed Jun 25 09:51:08 2014
> New Revision: 267858
> URL: http://svnweb.freebsd.org/changeset/base/267858
>
> Log:
>   xen/virtio: fix balloon drivers to not mark pages as WIRED
>
>   Prevent the Xen and VirtIO balloon drivers from marking pages as
>   wired. This prevents them from increasing the system wired page count,
>   which can lead to mlock failing because of hitting the limit in
>   vm.max_wired.

This change is conceptually wrong.
The pages balloon is allocating are unmanaged and they should be wired
by definition. Alan and I are considering enforcing this (mandatory
wired pages for unmanaged pages allocation) directly in the KPI.
This in practice just seem an artifact to deal with scarce  wired
memory limit. I suggest that for the XEN case this limit gets bumped
rather relying on similar type of hacks.

Attilio


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