stefan.lambrev at moneybookers.com
Thu Feb 7 01:43:24 PST 2008
Kris Kennaway wrote:
> Stefan Lambrev wrote:
>> 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://18.104.22.168/lock_profiling-8.txt
>> Finally I got pmcstat working - http://22.214.171.124/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
When I disable syncookies the server respond to more packets - from
250kpps enabled to 320kpps when disabled.
Can I disable syncache and how?
I'll try to increase syncache limits and will test again.
Btw is this expected - net.inet.tcp.syncache.count: -387.
I think this number should be always > 0.
More information about the freebsd-performance