if (!defined &_VM_PAGER_) {
    eval 'sub _VM_PAGER_ {1;}';
    eval 'sub PG_DFLT {-1;}';
    eval 'sub PG_SWAP {0;}';
    eval 'sub PG_VNODE {1;}';
    eval 'sub PG_DEVICE {2;}';
    eval 'sub PG_CLUSTERGET {1;}';
    eval 'sub PG_CLUSTERPUT {2;}';
    eval 'sub VM_PAGER_OK {0;}';
    eval 'sub VM_PAGER_BAD {1;}';
    eval 'sub VM_PAGER_FAIL {2;}';
    eval 'sub VM_PAGER_PEND {3;}';
    eval 'sub VM_PAGER_ERROR {4;}';
    eval 'sub VM_PAGER_AGAIN {5;}';
    if (defined &KERNEL) {
	eval 'sub vm_pager_cancluster {
	    local($p, $b) = @_;
	    eval "(($p)-> &pg_flags & ($b))";
	}';
    }
}
1;