RE: [PATCH 1/2] mm: Export vm_committed_as

KY Srinivasan
2012-10-08T03:36:00Z

> -----Original Message-----
> From: Greg KH [mailto:gregkh@linuxfoundation.org]
> Sent: Sunday, October 07, 2012 8:44 PM
> To: KY Srinivasan
> Cc: linux-kernel@vger.kernel.org; devel@linuxdriverproject.org; olaf@aepfle.de;
> apw@canonical.com; akpm@linux-foundation.org; andi@firstfloor.org
> Subject: Re: [PATCH 1/2] mm: Export vm_committed_as
>
> On Sun, Oct 07, 2012 at 04:59:45PM -0700, K. Y. Srinivasan wrote:
> > The policy engine on the host expects the guest to report the
> > committed_as. Since this variable is not exported,
> > export this symbol.
>
> Why are these symbols not needed by either Xen or KVM or vmware, which
> I think all support the same thing, right?

The basic balloon driver does not need this symbol since the basic balloon driver
is not automatically driven by the host. On the Windows host we have a policy engine that
drives the balloon driver based on both guest level memory pressure that the guest
reports as well as other system level metrics the host maintains. We need this symbol to
drive the policy engine on the host.

Regards,

K. Y