[openib-general] Serialization in ib_uverbs

[Boyd R. Faulkner]

I have a question about the intent of the mutex lock ib_uverbs_idr_mutex
used in kernel interface from user libraries.  It appears to be a lock on the 
idr linked lists but as a great many, if not all, of the ib_uverbs commands 
grab the mutex at the start of the function and hold it to the end, it acts 
to serialize all the library accesses to the kernel.  Is this intended?  

If a driver, say, waits for all references to an object to be removed before 
the close completes, all accesses stop while that occurs and if the command 
to make that happen needs that mutex, everything stops. I have seen this in 
practice.

Any insight would be appreciated.

Thanks,
Boyd

-- 
Boyd R. Faulkner
Open Grid Computing, Inc.
Phone:	512-343-9196 x109
Fax:	512-343-5450