From mboxrd@z Thu Jan 1 00:00:00 1970 From: "James Harper" Subject: RE: TODO in windows balloon driver Date: Sat, 26 Feb 2011 23:17:54 +1100 Message-ID: References: <291EDFCB1E9E224A99088639C47620228CF938AAE0@LONPMAILBOX01.citrite.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Return-path: Content-class: urn:content-classes:message In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: tinnycloud , xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org >=20 > HI James: >=20 > I've noticed the TODO tag in xenpci/xenpci_fdo.c, line 294 >=20 > 290 KdPrint((__DRIVER_NAME " Calling > HYPERVISOR_memory_op(XENMEM_populate_physmap) - pfn_count =3D %d\n", > pfn_count)); > 291 ret =3D HYPERVISOR_memory_op(xpdd, XENMEM_populate_physmap, > &reservation); > 292 ExFreePoolWithTag(pfns, XENPCI_POOL_TAG); > 293 KdPrint((__DRIVER_NAME " populated %d pages\n", ret)); > 294 /* TODO: what do we do if less than the required number of > pages were populated??? can this happen??? */ >=20 >=20 > Could we fix it in linux balloon driver way? > When no enough pfn_count got, give memory back to xen. > What do you think? > Thanks. I guess that would work, but then it would keep trying to decrease again every second. Maybe that's what we want but I'd rather put in some sort of backoff in there eg retry in one second then two seconds then 4 seconds etc up to a maximum of 1 minute or so, to reduce the noise. Are you seeing this happen? I'm guessing it's because xen doesn't have enough pages for you or because you've ballooned up above the maxmem limit or something... James