Andres Lagar-Cavilla
2009-Nov-30 19:10 UTC
[Xen-devel] [PATCH 03/14]: libxenlight, 8MB slack for PV domains
Contemplate 8MB of slack for PV domains, since they do ballooning (or flipping network rx) and need some extra room in their pfn space. Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.com> _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Vincent Hanquez
2009-Dec-01 06:34 UTC
Re: [Xen-devel] [PATCH 03/14]: libxenlight, 8MB slack for PV domains
On Mon, Nov 30, 2009 at 07:10:58PM +0000, Andres Lagar-Cavilla wrote:> Contemplate 8MB of slack for PV domains, since they > do ballooning (or flipping network rx) and need > some extra room in their pfn space. > > Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.com>this probably should be in the build structure. not magically adding 8 mb without the toolstack knowing, otherwise no toolstack can provide more or less slacks on a per domain basis. And it make precise memory handling a nightmare, and thus dynamic memory handling too. in some way this parameter is just like the shadow_memory one in the hvm build structure. -- Vincent _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Andres Lagar-Cavilla
2009-Dec-01 14:15 UTC
Re: [Xen-devel] [PATCH 03/14]: libxenlight, 8MB slack for PV domains
The 8mb slack is not real memory allocated. It''s extra room in the pfn space. The memory''s domain allocation remains capped at the amount intended. I haven''t seen anyone in xen-devel for five years needing more slack than that '') Particularly since the network rx flipping path stopped being the default Andres Vincent Hanquez wrote:> On Mon, Nov 30, 2009 at 07:10:58PM +0000, Andres Lagar-Cavilla wrote: > >> Contemplate 8MB of slack for PV domains, since they >> do ballooning (or flipping network rx) and need >> some extra room in their pfn space. >> >> Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.com> >> > > this probably should be in the build structure. not magically adding 8 mb without the > toolstack knowing, otherwise no toolstack can provide more or less slacks on a > per domain basis. And it make precise memory handling a nightmare, and thus > dynamic memory handling too. in some way this parameter is just like the > shadow_memory one in the hvm build structure. > >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel