Re: PLEASE HELP regarding System Tap

["Khushboo Goel" <kgoel at usc dot edu>]

>
>> I am working on what you have suggested, i will put a check when the
>> connection is over and will put delete that specific connection id
>> array.
>
> (Or even better - you could print the histogram for that connection at
> that time.)
>
>
>> Since its both space and time hungry so i have thought of
>> alternative way to write to life as i need to save the data wen i am
>> probing, so instead of putting in the aggregate variable i am
>> printing it to file, and checking how much its effecting CPU
>> Performance and instead of using histogram of the systemTap , i will
>> store it in some other file.
>
> You can do that too, but I wonder if your data needs are indeed as
> large as that first systemtap script suggested.  It appeared to be
> asking for a 100-bucket histogram (~1kB) for each of (say)
> ten-thousand tcp connections (10 MB storage during run).  ASCII
> pretty-printing each histogram could multiply the space by another
> factor of ~5, resulting in about 50 MB of output.  Is this about
> right?
>
>
 I am actually sending some 10Gb or data over 8 tcp connection from 1 cpu ..
But its post calculation so i don't think so i wana get into that ...


>> Is it possible i can know what address location is assigned to
>> system Tap buffer in the memory ??
>
> There are many different buffers.  You might be interested in the one
> the runtime can hand over via _stp_reserve(), but using that is not
> routinely recommended.

Can you tell me more about it or any documentation on it ??? i want to
go this runtime memory and write there directly.


----
I have observed one more thing , with the aggregate being in the code,
and i just remove one of the embedded C code , i don't get any buffer
overflow error, and it prints histogram and everything even for 20Gb
of data .. with NAGLE off and sending 64 Bytes packet ( 96Bytes
inclusive of header )
Which is strange coz i expected aggregate to show overflow buffer error
>
> - FChE
>