On Thu, 21 Nov 2013 17:09:27 +0100 Andreas Färber <afaer...@suse.de> wrote:
> Am 21.11.2013 15:34, schrieb Igor Mammedov: > > On Thu, 21 Nov 2013 15:13:12 +0100 > > Andreas Färber <afaer...@suse.de> wrote: > >> Am 21.11.2013 06:48, schrieb Li Guang: > >>> Why not give the memory that not be hot-added a chance to be placed on > >>> one memory slot? > >> > >> Seconded, I believe I requested that on the previous version already. > > Because current initial memory allocation is a mess and this already > > large series would become even more large and intrusive, so far series > > it relatively not intrusive and self contained. > > > > I believe re-factoring of initial memory to use Dimm devices should be > > done later on top of infrastructure this series provides. > > My problem with that is that that would be a semantically incompatible > modeling change. With your series we might have /machine/dimm.0/child[0] > be the first hot-plugged memory and once such a refactoring is done, > child[0] silently becomes -m and child[1] is the hot-added one. I think there won't be silent change in child[0], since most likely initial RAM would require additional DimmBus (maybe even 2) for it's devices. But anyway, why would this be an issue? > So if we know that we want/need to change the infrastructure, why not > add a single patch (?) to allocate one additional object on the bus now? > Unless we actually write the code, we won't know whether there are some > incorrect hot-plug assumptions in the dimm code. It wouldn't be a single simple patch for PC, I'm afraid. I don't see point in adding dummy DIMM device for initial memory and then do re-aliasing of its memory region in GPA as it's done in current code. As I see it (taking in account Marcolo's/Paolo's alignment path), current single MR for initial RAM should be split in 1-4 separate MRs depending on initial RAM amount and alignment requirements between HPA/GPA addresses. That would probably introduce additional, non hotlugable DimmBus-es (1-2) for low and high memory, which would be incompatible with old machine types devices and GPA layout, so why care about what /machine/dimm.0/child[0] would be in new machine version? > Andreas >
