gettimeofday() in hping
Kris Kennaway
kris at FreeBSD.org
Mon Feb 4 02:55:01 PST 2008
Stefan Lambrev wrote:
> Greetings,
>
> Kris Kennaway wrote:
>> Kris Kennaway wrote:
>>
>>>> Fixing all of the above I can send at about 13MB/sec (timecounter is
>>>> not relevant any more). The CPU is spending about 75% of the time
>>>> in the kernel, so
>>> that is the next place to look. [hit send too soon]
>>
>> Actually 15MB/sec once I disable all kernel debugging. This is
>> identical to Linux 2.6.24 on the same hardware. The patch I use to
>> fix hping brain-damage is attached.
>>
>> Kris
> Indeed this patch highly improve results (x2) under FreeBSD. On my
> hardware the max speeds under FreeBSD i still little slower compared to
> Linux (something like 19 vs 19.5 MB/s)
> but the speed is quite more stable under FreeBSD (under linux the
> average speed seems slower)
>
> I didn't tested the patch under linux but will do soon.
> Thanks for the help :)
>
> BTW 262144 is little high as this match the default value in FreeBSD, I
> tested with twice smaller buffer and do not see performance lost.
> Kris if you do not mind I'll write to hping developers to adopt this
> patch, and if no response from them I can try to reach the port
> maintainer, so we have this patched in ports?
>
My patch is a bit crude, because I didnt have the courage to digest the
entire structure of the code, so it may be slightly wrong with respect
to other operating modes (the #if 0 part is wrong, but that code needs
to be rewritten). Some version of it should be included in the software,
but perhaps after renaming the patch file ;-)
Kris
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