Running sp_who2 and following the BlkBy trail up to the root cause of blocking returns a SPID which has CPUTime and DiskIO values of 0; yet it's blocking 4 other SPIDs.
I'm confused by how this is possible; the CPUTime in particular seems odd as in order to obtain a lock you'd have had to have spent some time requesting resources / requesting the lock itself.
CPUTime is in milliseconds, so whilst it's possible that the requesting and locking of resources occurs fast enough to have a rounded down value here, that is a little surprising.
Also, these SPIDS are sometimes a few minutes old; yet appear to have done nothing beyond cause blocking.
How is it possible for a SPID to cause blocking whilst having zero CPU Time?
I'm asking as I suspect something's lacking in my understanding of the CPU Time stat. If anyone can advise on sensible steps to aid in investigating such issues though that would also be useful.