On Tue, 6 Oct 2015 14:29:53 +1100 David Gibson <da...@gibson.dropbear.id.au> wrote:
> On Mon, Oct 05, 2015 at 11:05:07AM +0200, Igor Mammedov wrote: > > On Mon, 5 Oct 2015 14:05:23 +0530 > > Bharata B Rao <bhar...@linux.vnet.ibm.com> wrote: > > > > > Size hotplug memory region assuming a 256MB max alignment every slot. > > > > > > Signed-off-by: Bharata B Rao <bhar...@linux.vnet.ibm.com> > > > --- > > > hw/ppc/spapr.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > > > index fc5e7d6..2ec509b 100644 > > > --- a/hw/ppc/spapr.c > > > +++ b/hw/ppc/spapr.c > > > @@ -1792,6 +1792,9 @@ static void ppc_spapr_init(MachineState *machine) > > > > > > spapr->hotplug_memory.base = ROUND_UP(machine->ram_size, > > > SPAPR_HOTPLUG_MEM_ALIGN); > > > + > > > + /* size hotplug region assuming 256M max alignment per slot */ > > > + hotplug_mem_size += SPAPR_MEMORY_BLOCK_SIZE * machine->ram_slots; > > Does target support hugepages backend? If it does then adjustment probably > > should be max supported hugepage alignment. > > Hrm, so the maximum possible page size on Power is 16G (though we > don't yet support that on "powernv" which is what the host system will > generally be). > > Not sure if the possibility of 16G "colossal pages" in future is > enough reason to put such a huge gap. There aren't any other page > sizes between 16MB and 16GB. Perhaps add a comment and a more verbose description in commit message about this so that in future not to wonder why 256 has been chosen.
