What's the status of parallel netisr?

[Kris Kennaway]

Jian Qiu wrote:
> Thanks again for the info.
> 
> As you suggested, I did test on the most recent 7.0-stable-200807 kernel.
> 
> The SMP throughout on the new kernel was improved to around 90MB/s.
> 
> However, SMP kernel still had no advantage over UP, at least for this
> kind of single threaded applications.
> 
> I further did the same test on Linux with both SMP and UP.
> 
> I did observe the same trend.
> 
> The throughput on UP (~210MB/ecs) was also much better than SMP (~170MB/sec).
> 
> However, I was surprised again that the local UDP throughput on Linux
> was more than double of FreeBSD.
> 
> Since all these tests were performed on the same machine, it must be
> because of the kernel that made such big differences.
> 
> I'm curious what is the major performance bottleneck in FreeBSD network stack??
> 
> Is there any plan in community to address these issues?

In our application-level tests FreeBSD significantly out-performs Linux, 
so either you have found a different workload, or something is not 
configured equally.  One important thing I can think of off the top of 
my head is that Linux has a larger socket buffer size by default, so try 
tuning that on FreeBSD or confirm they are equal.

If that still fails, can you provide test code?

Kris