Re: [PATCH 03/14]: libxenlight, 8MB slack for PV domains

[Andres Lagar-Cavilla <andres@lagarcavilla.com>]

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.
>
>