Hi all I notice that some fields in kvm_mmu_page struct record the unsync status of an mmu page. struct kvm_mmu_page { -> bool unsync; int root_count; /* Currently serving as active root */ -> unsigned int unsync_children; -> DECLARE_BITMAP(unsync_child_bitmap, 512); }; Moreover, some functions in mmu.c also relate to this so-called unsync mmu mechanism, like kvm_sync_page. Could anyone explain a bit about the unsync mmu and why it can boost the performance. Thx. -- Tianxiang Miao, Graduate Student, Institute of Parallel and Distributed Systems (IPADS), School of Software, Shanghai JiaoTong University -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html