[ofa-general] Re: [PATCHv2] IB/mad: fix duplicated kernel thread name

[Sean Hefty]

> Sorry but "improve data locality" is not enough information for me to 
> understand why the IB CM --neeed-- to spawn n kernel threads on my 
> n-core system, after all its slow path and the data does not moves on 
> QP1, what's the story here? and if it needs thread-per-cpu, why not use 
> the system threads/softirqs as does the TCP/IP stack connection mgmt code?

IMO, if we're going to have multiple cores, then we should create 
multiple threads to use them.  This becomes more important as the number 
of cores increases.  (The overhead of a non-running thread can't be that 
much.)  Stating that connection establishment is a slow path operation 
assumes that all connections are long lived.

The current behavior of the MAD layer is that all callbacks for a given 
registration are serialized.  We either need to preserve this 
functionality or verify that MAD users can handle simultaneous 
callbacks.  (Hopefully MAD users didn't make any assumptions regarding 
the threading model used by the MAD layer, but we need to verify this. 
I'm more worried about code in the MAD layer itself.)

- Sean