* it simply writes "START". As the first write is cold cache and
* the rest is hot, we save off that time in bm_first and it is
* reported as "first", which is shown in the second write to the
* it simply writes "START". As the first write is cold cache and
* the rest is hot, we save off that time in bm_first and it is
* reported as "first", which is shown in the second write to the