Am Mittwoch 20 Mai 2009 11:11:57 schrieb Avi Kivity: > > Yes, KSM is easier and it even finds duplicate data pages. > > On the other hand it does only provide memory saving. It does not speedup > > application startup like execute-in-place (major page faults become minor > > page faults for text pages if the page is already backed by the host) I > > am not claiming that KSM is useless. Depending on the scenario you might > > want the one or the other or even both. For typical desktop use, KSM is > > very likely the better approach > > If ksm shares pagecache, then doesn't it become effectively XIP?
Not exactly, only for long running guests with stable working set. If the guest boots up, its page cache is basically empty, but the shared segment is populated. its the startup where xip wins. Same is true for guests with quickly changing working sets. > We could also hook virtio dma to preemptively share pages somehow. Yes, that is something to think about. One idea that is used on z/VM by lot of customers is to have a shared disk read-only for /usr that is cached by the host. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
