On Thursday 17 January 2008 15:01:46 Anthony Liguori wrote: > Rusty Russell wrote: > > OTOH it's currently pretty obvious (and usually fatal) if the guest has > > trouble meeting the balloon requirements. A serious host needs a way of > > detecting stress in the guest anyway, which this doesn't offer until it's > > too late... > > The question I'm interested in answering though is not if but when. I > would like to know when the guest has reached it's target. I'm saying that it will be v. quickly in all but "too much squeeze" case. > And while we do get the madvise call outs, it's possible that pages have > been faulted in since then. But that's exactly what the balloon number *doesn't* tell you. It can tell you that it's released pages back to be used by the OS, but not whether the OS has used them. I think this number is good for debugging the balloon driver, but for anything else it's a false friend. Rusty. PS. Please cut down mails when you reply. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
