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

KY Srinivasan
2012-10-10T03:18:54Z

> -----Original Message-----
> From: Andrew Morton [mailto:akpm@linux-foundation.org]
> Sent: Tuesday, October 09, 2012 9:17 PM
> To: KY Srinivasan
> Cc: Greg KH; olaf@aepfle.de; linux-kernel@vger.kernel.org; andi@firstfloor.org;
> apw@canonical.com; devel@linuxdriverproject.org
> Subject: Re: [PATCH 1/2] mm: Export vm_committed_as
>
> On Wed, 10 Oct 2012 00:11:28 +0000 KY Srinivasan <kys@microsoft.com> wrote:
>
> >
> >
> > > -----Original Message-----
> > > From: Andrew Morton [mailto:akpm@linux-foundation.org]
> > > Sent: Tuesday, October 09, 2012 3:48 PM
> > > To: Greg KH
> > > Cc: KY Srinivasan; olaf@aepfle.de; linux-kernel@vger.kernel.org;
> > > andi@firstfloor.org; apw@canonical.com; devel@linuxdriverproject.org
> > > Subject: Re: [PATCH 1/2] mm: Export vm_committed_as
> > >
> > > On Mon, 8 Oct 2012 06:35:39 -0700
> > > Greg KH <gregkh@linuxfoundation.org> wrote:
> > >
> > > > On Mon, Oct 08, 2012 at 03:35:50AM +0000, KY Srinivasan wrote:
> > > > >
> > > > >
> > > > > > -----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.
> > > >
> > > > Ok, but you're going to have to get the -mm developers to agree that
> > > > this is ok before I can accept it.
> > >
> > > Well I guess it won't kill us.
> >
> >
> > Thanks.
> >
>
> The other part of my email seems to have vanished. Which makes me sad,
> because I was rather interested in the answer.

Andrew,

I am truly sorry for not answering your question. To be honest, I was not quite sure
what the issue was, given from what I can tell, the vm_committed_as is maintained
globally and would represent the overall memory commitment of the system. Is this not the
case.

Regards,

K. Y