Mulyadi Santosa wrote: > Hi Victor... > > On 11/13/09, Victor Vasilchenko <vvasilche...@gmail.com> wrote: > > The only BIG question - what virtualization software can support MPI to > > effectively work on cluster ? > > > > I am asking this question to QEMU team cause I believe QEMU can be the one. > > If you have any ideas or experiments or information - please share with me. > > > > Kind Regards, > > Victor. > > > > If you check through Qemu list archieve, you shall see that there were > more or less similar question: parallelization of Qemu.
> Most of the answers are: it can be hardly done. AFAIK, this is due > to how dynamic translation is done... you need (most of the part I > guess) almost 100% serialization. I completely disagree. Dynamic translation doesn't need 100% serialisation, but to relax that it does require atomic ops and memory barriers (including implied ones) in the guest to be translated to equivalents in the host. Unfortunately x86 instructions imply a lot of barriers (program-ordered writes), which is great for programming x86 but not great when translating to non-x86 host code. Right now, though, qemu's translator does not do that, even for x86->x86, so it has to be serialised when running multi-CPU guest code. KVM, on the other hand, does not do dynamic translation and can run multiple threads in parallel because the atomic/barrier semantics are preserved exactly. KVM would be a fine candidate for running multiple threads on different host machines. You'd need to serialise memory using page faults, but such techniques are already implemented with cluster filesystems and writable-mmap'd files, so it might be possible to use KVM over that. -- Jamie
