Javier Guerra wrote: > On 3/4/08, Avi Kivity <[EMAIL PROTECTED]> wrote: > >> apply to kvm guests. With mmu notifiers, the trend will grow even stronger. >> > > 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 - 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 -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- 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
