[rds-devel] Re: [PATCH RFC RDS/IB] version 2. increase number of unsignaled work requests

Zach Brown zach.brown at oracle.com
Thu Jan 25 16:43:40 PST 2007


> Although the code does not have interleaving fragments from different
> messages, it seems that multiple RDS messages can be in-flight
> simultaneously because rds_send_xmit() does not wait for completions:

Right, that's correct.

I think I finally see what you're getting at, though.  We want to  
delay signaling completions just enough to get the batching benefits  
but not so much that we create dead time on the wire.

Is there some rule of thumb about when the benefits of batching  
completions starts to diminish?  Some number of work requests /  
completion or amount transfered / completion or interrupts / cpu,  
anything like that?

Anyway, your reasoning sounds valid.  It should be well commented in  
the patch, of course.

- z



More information about the rds-devel mailing list