network performance

[Stefan Lambrev]

Greetings,

In my desire to increase network throughput, and to be able to handle 
more then ~250-270kpps
I started experimenting with lagg and link aggregation control protocol 
(lacp).
To my surprise this doesn't increase the amount of packets my server can 
handle

Here is what netstat reports:

netstat -w1 -I lagg0
            input        (lagg0)           output
   packets  errs      bytes    packets  errs      bytes colls
    267180     0   16030806     254056     0   14735542     0
    266875     0   16012506     253829     0   14722260     0

netstat -w1 -I em0
            input          (em0)           output
   packets  errs      bytes    packets  errs      bytes colls
    124789 72976    7487340     115329     0    6690468     0
    126860 67350    7611600     114769     0    6658002     0

netstat -w1 -I em2
            input          (em2)           output
   packets  errs      bytes    packets  errs      bytes colls
    123695 65533    7421700     113575     0    6584856     0
    130277 62646    7816626     113648     0    6592280     0
    123545 64171    7412706     113714     0    6596174     0

Using lagg doesn't improve situation at all, and also errors are not 
reported.
Also using lagg increased content switches:

 procs      memory      page                   disk   faults      cpu
 r b w     avm    fre   flt  re  pi  po    fr  sr ad4   in   sy   cs us 
sy id
 1 0 0   81048 1914640    52   0   0   0    50   0   0 3036 37902 13512  
1 20 79
 0 0 0   81048 1914640    13   0   0   0     0   0   0 9582   83 22166  
0 56 44
 0 0 0   81048 1914640    13   0   0   0     0   0   0 9594   80 22028  
0 55 45
 0 0 0   81048 1914640    13   0   0   0     0   0   0 9593   82 22095  
0 56 44

Top showed for CPU states +55%   system, which is quite high?

I'll use hwpmc and lock_profiling to see where the kernel spends it's time.

-- 

Best Wishes,
Stefan Lambrev
ICQ# 24134177