Re: rps perfomance WAS(Re: rps: question

Changli Gao
2010-04-14T22:51:50Z

On Thu, Apr 15, 2010 at 4:57 AM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
>
> RPS can be tuned (Changli wants a finer tuning...), it would be
> intereting to tune multiqueue devices too. I dont know if its possible
> right now.
>
> On my Nehalem machine (16 logical cpus), its NetXtreme II BCM57711E
> 10Gigabit has 16 queues. It might be good to use less queues according
> to your results on some workloads, and eventually use RPS on a second
> layering.

My idear is: run a daemon in userland to monitor the softnet
statistics, and tun the RPS setting if necessary. It seems that the
current softnet statistics data isn't correct.

Long time ago, I did a test, and the conclution was
call_function_single IPI was more expensive than resched IPI, so I
moved to kernel thread from softirq for packet processing. I'll redo
the test later.

--
Regards，
Changli Gao(xiaosuo@gmail.com)