> > > > could you (or anybody) elaborate on that? the mmu-related threads show > > lots of progress, but it's way (way) out of my league. > > > > AFAICT, it's about the infrastructure to later write drivers (virtio?) > > to DMA-heavy hardware (IB, RDMA, etc). am i wrong? or is it > > something more complete (like a ready to use driver)? > > > > > > mmu notifiers provide a way for the core Linux memory management code to > propagate changes in how Linux views a process' memory map to external > memory management units that are also interested in that memory map. > These changes include things like swapping, page migration, changes to > memory protection, defragmentation, and copy-on-write. In this context, > kvm appears as a dma capable memory controller, like RDMA NICs or GPUs. > > For kvm, this is important as it allows all those features to be used > transparently with guests. > > - swapping allows you to overcommit memory
Normally swapping mechanism choose the Least Recently Used(LRU) pages of a process to be swapped out. When KVM uses MMU notifier in linux kernel to implement swapping for VM, could KVM choose LRU pages of a VM to swap out? If so, could you give a brief description about how this is implemented? > - page migration allows optimization of memory placement within the host > in response to changing workloads > - defragmentation will allow (if/when it is merged into Linux) more > widespread use of large pages, which improve performance > - copy-on-write allows sharing identical pages of memory among guests, > increasing guest density Thanks, Forrest ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
