On 07/09/2017 11:20, Alexey Kardashevskiy wrote: > > /* Accessed via RCU. */ > struct FlatView *current_map; > > int ioeventfd_nb; > struct MemoryRegionIoeventfd *ioeventfds; > - struct AddressSpaceDispatch *dispatch; > - struct AddressSpaceDispatch *next_dispatch; > +
The rough idea of the patch matches my suggestion indeed. However, I am not sure why all of the changes in patch 2 are needed. Once you have built the FlatView and the dispatch within it, you can still cache its dispatch tree in as->dispatch, and free it with RCU from flatview_destroy. This removes the need to use call_rcu from flatview_unref. In addition, you could change the computation of FlatView's root to resolve 2^64-sized aliases; also set it to NULL if the AddressSpace's root is disabled or the alias it resolves to is disabled (and so on recursively until a non-alias is found). This should remove the need for address_space_root() and the change to pci_init_bus_master. Paolo
