80 /* * The UVM memory object interface. Notes: * * A UVM memory object represents a list of pages, which are managed by * the object's pager operations (uvm_object::pgops). All pages belonging * to an object are owned by it and thus protected by the object lock. * * The lock (uvm_object::vmobjlock) may be shared amongst the UVM objects. * By default, the lock is allocated dynamically using mutex_obj(9) cache. * Lock sharing is normally used when there is an underlying object. For * example, vnode representing a file may have an underlying node, which * is the case for tmpfs and layered file systems. In such case, vnode's * UVM object and the underlying UVM object shares the lock (note that the * vnode_t::v_interlock points to uvm_object::vmobjlock). * * The reference count is managed atomically for the anonymous UVM objects. * For other objects, it is arbitrary (may use the lock or atomics). */