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Re: PLEASE HELP regarding System Tap


Hi -


> 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?


> 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.

- FChE


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