Re: reading the SGA from my own program

Hi Tanel,

You have to map all the segments, and I always use them with any conversion. I have a little program called websga and you can browse and search in the SGA with a browser instead of a debugger (so much simpler and nicer), this program maps all segments but has to check for gaps if it starts searching for addresses and contents of addresses.

Anjo.

On 8/19/06, Tanel Poder <tanel.poder.003_at_mail.ee> wrote:
>
> Why bother at all with those calculations?
>
> Just map all SGA SHM segments at the same locations in your program where
> they'd be mapped in an oracle processes and use all SGA addresses without
> any conversion needed.
>
> Even if some data is stored in different shared memory segments, it's
> still the same virtual address space - no need for doing some segment offset
> calcuations...
>
> Tanel.
>
> ------------------------------
> *From:* oracle-l-bounce_at_freelists.org [mailto:
> oracle-l-bounce_at_freelists.org] *On Behalf Of *Jeremiah Wilton
> *Sent:* Saturday, August 19, 2006 05:14
> *To:* 'Oracle Discussion List'
> *Subject:* reading the SGA from my own program
>
>
>
> I am trying to play around with reading the SGA using my own program, as
> popularized by Kyle Hailey and Miladin Modrakovic's papers and
> presentations. I am confused about where to find x$ksusecst (session wait)
> and other items in the fixed area.
>
>
>
> The base address of the SGA from x$ksmmem is hex 20000000.
>
>
>
> The lowest ADDR I see in x$ksusecst on my instance is 27133F24. So far so
> good.
>
>
>
> That means that x$ksusecst begins (27133F24-20000000=7133F24) bytes into
> the segment containing the fixed SGA, right?
>
>
>
> Hex 7133F24 is decimal 118,701,860, so that should be about 113Mb into the
> segment.
>
>
>
> The problem is that the segment containing my fixed area (from oradebug
> ipc) is only 4Mb. All the shared memory segments owned by oracle on my host
> (according to ipcs -a) total less than 108Mb.
>
>
>
> So according to x$ksusecst(ADDR), session waits have an address beyond the
> highest address in the SGA. What am I getting wrong?
>
>
>
> Thanks for any insights!
>
> --
>
> Jeremiah Wilton
>
> ORA-600 Consulting
>
> http://www.ora-600.net
>
>

-- 
Anjo Kolk
Owner and Founder OraPerf Projects
tel:    +31-577-712000
mob: +31-6-55340888

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