On Sun, Apr 21, 2013 at 03:19:21PM +0200, Paolo Bonzini wrote: > Il 20/04/2013 19:02, Michael S. Tsirkin ha scritto: > >> > I guess the opposite sense could be named 'x-rdma-pin-all'; default > >> > false means to do chunk registration and release, > > chunk release only happens after migration is complete unfortunately. > > This means that eventually all initialized memory is pinned, regardless > > of the setting (this is fixable but there's no plan to fix this, at this > > point). So pin-all might be misleading to some. > > > > I agree 'chunk' is unnecessarily low level though. > > The only difference ATM is pinning of uninitialized memory so I think a > > better name would be 'x-rdma-pin-uninitialized' or some such. > > > > x-rdma-pin-all is a better choice. x-rdma-pin-uninitialized is also too > low level. > > Since this series is likely to miss 1.5 at this point, we could > implement the unregistration part of the protocol in the destination. > This way, any heuristic we add to the source will not break backwards > compatibility. > > Paolo
To test, you'll have to implement it in the source too. That's probably a good idea anyway, though doing this efficiently might need more thought, and some of the tricks I described earlier (pipelining, registration cache) might be needed. Though I'm curious what the performance impact would be even without these tricks. -- MST
