* CACHE_SET_STOPPING always gets set first when we're closing down a cache set;
* we'll continue to run normally for awhile with CACHE_SET_STOPPING set (i.e.
* flushing dirty data).
* CACHE_SET_STOPPING always gets set first when we're closing down a cache set;
* we'll continue to run normally for awhile with CACHE_SET_STOPPING set (i.e.
* flushing dirty data).