rddir_cache_alloc
rrdc = rddir_cache_alloc(KM_NOSLEEP);
nrdc = rddir_cache_alloc(KM_SLEEP);
rrdc = rddir_cache_alloc(KM_NOSLEEP);
nrdc = rddir_cache_alloc(KM_SLEEP);
extern rddir_cache *rddir_cache_alloc(int);