[openib-general] A new simple ulp (SPTS)

[Jeff Carr]

On 06/23/2005 09:52 AM, Talpey, Thomas wrote:
> At 12:43 PM 6/22/2005, Jeff Carr wrote:
> 
>>On 06/21/2005 12:50 PM, Roland Dreier wrote:
>>
>>
>>>What happens if you try replacing the send_flags line with the one you
>>>have commented out?
>>>
>>>+	// send_wr.send_flags = IB_SEND_SIGNALED;
>>
>>Thanks, you are correct. IB_SEND_SIGNALED gives me the behavior I was
>>expecting.
> 
> 
> By the way, unsignaled sends can work very well indeed, but you have to be
> sure to poll for completions at regular intervals. Basically, what you're doing
> is ensuring that software (mthca) gets control from time to time, either via
> an interrupt (signaled) or poll (unsignaled).
> 
> It's quite a challenge to get the polling right, but the reduction in interrupts
> can be a win. The NFS/RDMA module does this, but it takes the approach

I didn't know there was a nfs/rmda module?

root at jcarr:/test/gen2# find . |grep -i nfs
root at jcarr:/test/gen2#

> of "occasionally" posting a signaled send. The trick is getting the value of
> "occasionally" right. :-)

Yep, I understand the tuning problems; that is what I need.
Jeff