[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: network performance



Stefan Lambrev wrote:
Greetings,

Kris Kennaway wrote:
Stefan Lambrev wrote:

I'll use again hwpmc and LOCK_PROFILING to see what's going on.
And will try the same benchmark on quad core processor as now numbers of cores/cpus matter :)

Here are promised results - http://89.186.204.158/lock_profiling-8.txt
Finally I got pmcstat working - http://89.186.204.158/hwpmc-p4.txt
The stats are gathered during 600kpp incoming.
I think that syncache or what calls MD5Transform is not SMP able, and that's why outgoing 250kpps is the limit that I can't beat.

It looks like the syncache is using most of the CPU time. However you are not hitting problems caused by lack of concurrency there. It does do a *lot* of work with the syncache mutex held (including generation of the cookie, which involves MD5) so it might be an issue in the future, but there are other bottlenecks in the way before that is your main issue. Things may be different with more CPUs.

Did you compare to what happens to performance when the syncache is disabled?

Kris

_______________________________________________
freebsd-performance_(_at_)_freebsd_(_dot_)_org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-performance
To unsubscribe, send any mail to "freebsd-performance-unsubscribe_(_at_)_freebsd_(_dot_)_org"