Re: bge(4) and softint-based if_input

[Taylor R Campbell <campbell+netbsd-tech-net%mumble.net@localhost>]

   Date: Wed, 24 Feb 2016 16:19:39 +0000 (GMT)
   From: Robert Swindells <rjs%fdy2.co.uk@localhost>

   I am seeing very slow responses to received packets to a bge(4)
   controller since the change to run if_input in a softint.

What does `slow' mean here?  What are you measuring?

Can you use dtrace to measure the latency from hard interrupt to soft
interrupt to packet processing, or various points in between?

   One thought was whether it would help to take out the call to
   softint_schedule() from if_percpuq_enqueue() and call it explictly
   after a batch of mbufs have been enqueued.

Could try that.  I expect softint_schedule is pretty cheap, though.