On 14-06-25 11:52 PM, Peter Crosthwaite wrote: > On Thu, Jun 26, 2014 at 4:58 AM, Paolo Bonzini <pbonz...@redhat.com> wrote: >> Il 25/06/2014 19:53, Etienne Martineau ha scritto: >> >>> >>> It seems to me that there is a scale issue O(n) in >>> memory_region_transaction_commit(). >>> >>> Basically the time it takes to rebuild the memory view during device >>> assignment >>> pci_bridge_update_mappings() increase linearly with respect to the number >>> of >>> device already assigned to the guest. >> >> >> That's correct, unfortunately. It can be fixed, it's not hard but also not >> trivial. >> >> Basically you can detect address spaces whose memory region is an alias of >> an address space's root memory region. You can then reuse that address >> space's FlatView instead of building another one. >> > > Sounds like my shareable address spaces scheme: > > http://lists.gnu.org/archive/html/qemu-devel/2014-06/msg00366.html > > Its not MR alias aware but shouldn't be too hard to extend. Would this help? > > Regards, > Peter > >> Paolo >>
Hi Peter, I 'think' I understand what you are proposing. My problem is that a) I don't see how to covert pci_bridge to that PMA model and b) I'm not sure if this is going to address the issue I'm facing and if yes then how ? thanks, Etienne
