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.
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.

I had another question

Is it possible i can know what address location is assigned to system
Tap buffer in the memory ??


On Tue, Jul 8, 2008 at 1:45 PM, Stone, Joshua I
<joshua.i.stone@intel.com> wrote:
> Frank Ch. Eigler wrote:
>> Looking at your script, you are doing one space-hungry and one
>> time-hungry thing that may each need change.  Your npr_pktsize[] array
>> will be both tall and wide -- potentially many elements, each a wide
>> histogram.  That will consume lots of memory to store.  The whole
>> array will also take lots of time (statements) and (buffer) space to
>> print out with that unlimited foreach().  Depending on which resource
>> systemtap detects as exhausted, you may get different error messages.
>> For each of them, there is some sort of countermeasure.
>
> Also, it might be helpful to find a reasonable "end-of-connection" probe point for a given connection id.  At that point you could print the accumulated data for that connection and delete it from the array.  If npr_pktsize only contains the currently active connections, you'll probably have a much better bound on the size.
>
> Josh
>