7.0-release / systat / 3GB

[Zbigniew Szalbot]

Hello,

Kris Kennaway:
> Wojciech Puchar wrote:
>>> I am a bit curious though why once the outgoing bandwidth exceeds 
>>> (more or less) 3GB, the Total counter gets reset and starts counting 
>>> from scratch.
>> isn't it 4GB - because of 32-bit unsigned counter?
> 
> I would guess so.
> 
> Using a 64-bit counter on 32-bit systems would cause additional 
> processing overhead for little benefit.

I have confirmed (with assistance from Wojtek Puchar) that the problem 
of resetting a Total counter for 'systat -ifstat' happens every 4GB (not 
3GB) amount of data. It only affects i386 machines. amd64 machines are 
not affected.

I have tested this on 7.0 and 6.1-Release versions. Here's an example

em0  in    104.564 KB/s        104.564 KB/s            2.401 GB
      out   220.282 KB/s        284.090 KB/s            3.874 GB

em0  in     17.416 KB/s        220.306 KB/s            2.404 GB
      out   257.781 KB/s        284.090 KB/s            3.902 GB

em0  in     35.181 KB/s        803.832 KB/s            2.420 GB
      out   170.575 KB/s        284.090 KB/s            3.980 GB

em0  in     11.020 KB/s        803.832 KB/s            2.423 GB
      out    27.773 KB/s        284.090 KB/s            3.998 GB

em0  in      5.515 KB/s        803.832 KB/s            2.423 GB
      out    97.953 KB/s        284.090 KB/s            4.000 GB

em0  in      7.944 KB/s        803.832 KB/s            2.423 GB
      out    71.475 KB/s        284.090 KB/s           25.019 KB

I have submitted a pr in case this can be fixed.

http://www.freebsd.org/cgi/query-pr.cgi?pr=125196

Thanks!
-- 
Zbigniew Szalbot
www.LCWords.com
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